Exhibit 99.1

DUKE ENERGY CorporatioN

35,000,000 Equity Units

UNDERWRITING AGREEMENT

August 10, 2026

Barclays Capital Inc.

BofA Securities, Inc.

Mizuho Securities USA LLC

As Representatives of the several Underwriters

Ladies and Gentlemen:

1.      Introductory. DUKE ENERGY Corporation, a Delaware corporation (the “Corporation”), proposes, subject to the terms and conditions stated herein, to issue and sell to the several Underwriters an aggregate of 35,000,000 Equity Units (initially in the form of Corporate Units as defined below) (the “Underwritten Securities”), the terms of which are set forth on the pricing term sheet attached as Schedule C hereto. Additionally, the Corporation proposes to issue and sell to the several Underwriters, for the sole purpose of covering over-allotments in connection with the sale of the Underwritten Securities, at the option of the Underwriters, up to an additional 5,000,000 Equity Units (initially in the form of Corporate Units as defined below) (the “Option Securities”). The Underwritten Securities and any Option Securities are herein referred to as the “Securities.”

Each Equity Unit will initially consist of (a)(i) a 1/40 or 2.5% undivided beneficial ownership interest in $1,000 principal amount of the Corporation’s 4.85% Remarketable Senior Notes due 2032 (the “2032 RSNs”) and (ii) a 1/40 or 2.5% undivided beneficial ownership interest in $1,000 principal amount of the Corporation’s 4.85% Remarketable Senior Notes due 2036 (the “2036 RSNs” and, together with the 2032 RSNs, the “RSNs”) and (b) a stock purchase contract (a “Purchase Contract”) under which the holder of an Equity Unit will purchase from the Corporation on August 1, 2029, for an amount in cash equal to the stated amount per Security of $50, a number of shares of common stock, par value $0.001 per share, of the Corporation (the “Common Stock”), as set forth in such Purchase Contract. The RSNs will be issued pursuant to the provisions of an Indenture, dated as of June 3, 2008, (the “Original Indenture”) as supplemented by separate supplemental indentures establishing the respective terms of the 2032 RSNs and the 2036 RSNs, to be dated as of the Closing Date (as defined in Section 3) (each a “Supplemental Indenture” and, together with the Original Indenture, the “Indenture”), each between the Corporation and The Bank of New York Mellon Trust Company, N.A. (formerly known as The Bank of New York Trust Company, N.A.), as trustee (the “Trustee”).

In accordance with the terms of a Purchase Contract and Pledge Agreement (the “Purchase Contract and Pledge Agreement”) to be entered into among the Corporation, The Bank of New York Mellon Trust Company, N.A., as Purchase Contract Agent (the “Purchase Contract Agent”), The Bank of New York Mellon Trust Company, N.A., as Custodial Agent (the “Custodial Agent”), The Bank of New York Mellon Trust Company, N.A., as Collateral Agent (the “Collateral Agent”) and The Bank of New York Mellon Trust Company, N.A., as Securities Intermediary (the “Securities Intermediary”), the holders of the Equity Units will pledge the RSNs to secure the holders’ obligations to purchase Common Stock under the Purchase Contracts. The Purchase Contracts will be issued pursuant to the Purchase Contract and Pledge Agreement. The Purchase Contracts and the Purchase Contract and Pledge Agreement are herein collectively referred to as the “Units Agreements.” The Purchase Contracts, together with the related RSNs, are herein referred to as “Corporate Units.” A holder of Corporate Units, at its option, may elect to create “Treasury Units” by substituting pledged U.S. treasury securities for any pledged ownership interests in the RSNs. Unless otherwise indicated, the term “Equity Units” includes both Corporate Units and Treasury Units.

Pursuant to a Remarketing Agreement, to be entered into by the Corporation and the Purchase Contract Agent, as the purchase contract agent and attorney-in-fact for the holders of the Equity Units, and the remarketing agent(s) named therein (the “Remarketing Agents”), in such form and dated as of such date as to be determined by the parties thereto (the “Remarketing Agreement”), the RSNs will be remarketed, subject to certain terms and conditions.

Barclays Capital Inc., BofA Securities, Inc. and Mizuho Securities USA LLC (the “Representatives”) are acting as representatives of the several underwriters named in Schedule A hereto (together with the Representatives, the “Underwriters”). The Corporation understands that the several Underwriters propose to offer the Securities for sale upon the terms and conditions contemplated by (i) this Agreement and (ii) the Base Prospectus, the Preliminary Prospectus and the Permitted Free Writing Prospectus (each as defined below) issued at or prior to the Applicable Time (as defined below) (the documents referred to in the foregoing subclause (ii) are referred to herein as the “Pricing Disclosure Package”).

2.      Representations and Warranties of the Corporation. The Corporation represents and warrants to, and agrees with, the several Underwriters that:

3.      Purchase, Sale and Delivery of Securities. On the basis of the representations, warranties and agreements herein contained, but subject to the terms and conditions herein set forth, (a) the Corporation agrees to sell to the Underwriters, and the Underwriters agree, severally and not jointly, to purchase from the Corporation, at a purchase price of $49.125 per Security, the number of Underwritten Securities set forth opposite the names of the Underwriters in Schedule A hereto, and (b) in the event the Underwriters exercise their option to purchase Option Securities, the Corporation agrees to sell to the Underwriters, and the Underwriters agree, severally and not jointly, to purchase from the Corporation at the same price set forth in clause (a) of this Section 3, that portion of the Option Securities as to which such option to purchase was exercised, and each Underwriter agrees, severally and not jointly, to purchase the number of Option Securities (subject to such adjustments to eliminate fractional Securities as the Underwriters may determine) that bears the same proportion to the total number of Option Securities to be purchased on such Option Closing Date as the number of Underwritten Securities set forth opposite the names of the Underwriters in Schedule A hereto bears to the total number of Underwritten Securities.

The Corporation hereby grants to the Underwriters the right to purchase at an Option Closing Date that will occur on or prior to the 13th calendar day immediately following, and including, the Closing Date, up to 5,000,000 Option Securities, at the same purchase price as set forth in clause (a) of the first paragraph of this Section 3, for the sole purpose of covering over-allotments. Any such election to purchase Option Securities shall be exercised only by written notice from the Representatives to the Corporation setting forth the number of Option Securities to be purchased and the date on which such Option Securities are to be delivered, as determined by the Representatives, but in no event earlier than the Closing Date.

Payment of the purchase price for the Underwritten Securities to be purchased by the Underwriters shall be made to the Corporation by wire transfer of immediately available funds, payable to the order of the Corporation against delivery of the Underwritten Securities, initially in the form of Corporate Units, in fully registered form, to you or upon your order at 10:00 a.m., New York City time, on August 13, 2026 or such other time and date as shall be mutually agreed upon in writing by the Corporation and the Representatives (the “Closing Date”). Payment of the purchase price for any Option Securities to be purchased by the Underwriters shall be made to the Corporation by wire transfer of immediately available funds, payable to the order of the Corporation, against delivery of such Option Securities, initially in the form of Corporate Units, in fully registered form, to you or upon your order at 10:00 a.m., New York City time, or as soon as possible thereafter, on the date specified in the notice described in this Section 3, or such other time and date as shall be mutually agreed upon in writing by the Corporation and the Representatives (each, an “Option Closing Date”).

The Underwritten Securities and any Option Securities shall be represented by one or more definitive global securities in book-entry form, in such authorized denominations as established pursuant to the Units Agreements, and shall be deposited by or on behalf of the Corporation with The Depository Trust Company (“DTC”) or its designated custodian and registered in the name of Cede & Co., as nominee for DTC. All other documents referred to herein that are to be delivered at the Closing Date or any Option Closing Date shall be delivered at that time at the offices of Sidley Austin llp, 787 Seventh Avenue, New York, New York 10019.

4.      Public Offering by the Underwriters. It is understood that the several Underwriters propose to offer the Securities for sale to the public as set forth in the Pricing Disclosure Package and the Prospectus.

5.     Covenants of the Corporation. The Corporation covenants and agrees with the several Underwriters that:

6.            Conditions of the Obligations of the Underwriters. The obligations of the several Underwriters to purchase and pay for the Securities on the Closing Date or any Option Closing Date, as applicable, will be subject to the accuracy of the representations and warranties on the part of the Corporation herein, at the date of this Agreement and the Closing Date or any Option Closing Date, as applicable, to the accuracy of the statements of officers of the Corporation made pursuant to the provisions hereof, to the performance by the Corporation of its obligations hereunder and to the following additional conditions precedent:

Such counsel may state that such counsel’s opinions in paragraphs (vii), (viii), (ix) and (x) above are subject to the effects of bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other similar laws relating to or affecting creditors’ rights generally, and by general principles of equity (whether enforceability is considered in a proceeding in equity or at law) and an implied covenant of good faith and fair dealing. Such counsel shall state that nothing has come to such counsel’s attention that has caused such counsel to believe that each document incorporated by reference in the Registration Statement, the Pricing Disclosure Package and the Prospectus, when filed, was not, on its face, appropriately responsive, in all material respects, to the requirements of the 1934 Act and the 1934 Act Regulations. Such counsel shall also state that nothing has come to such counsel’s attention that has caused such counsel to believe that (i) the Registration Statement, as of the effective date with respect to the Underwriters pursuant to Rule 430B(f)(2) of the 1933 Act Regulations, contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) the Pricing Disclosure Package at the Applicable Time contained any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading or (iii) that the Prospectus, as of its date or at the Closing Date and any Option Closing Date, as applicable, contained or contains any untrue statement of a material fact or omitted or omits to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. Such counsel may also state that, except as otherwise expressly provided in such opinion, such counsel does not assume any responsibility for the accuracy, completeness or fairness of the statements contained in or incorporated by reference into the Registration Statement, the Pricing Disclosure Package or the Prospectus and does not express any opinion or belief as to (i) the financial statements or other financial and accounting data contained or incorporated by reference therein or excluded therefrom, including XBRL interactive data, (ii) the statement of the eligibility and qualification of the Trustee included in the Registration Statement (the “Form T-1”) or (iii) the information in the Pricing Disclosure Package and the Prospectus under the caption “Book-Entry System.”

In rendering the foregoing opinion, such counsel may state that such counsel does not express any opinion concerning any law other than the law of the State of North Carolina or, to the extent set forth in the foregoing opinions, the federal securities laws and may rely as to all matters of the laws of the States of South Carolina, Ohio, Indiana and Florida on appropriate counsel reasonably satisfactory to the Representatives, which may include the Corporation’s other “in-house” counsel. Such counsel may also state that such counsel has relied as to certain factual matters on information obtained from public officials, officers of the Corporation and other sources believed by such counsel to be reliable.

You shall also have received a statement of Hunton Andrews Kurth LLP, dated the Closing Date and any Option Closing Date, as applicable, to the effect that:

(i) no facts have come to such counsel’s attention that have caused such counsel to believe that the documents filed by the Corporation under the 1934 Act and the 1934 Act Regulations that are incorporated by reference in the Preliminary Prospectus Supplement that forms a part of the Pricing Disclosure Package and the Prospectus, when filed, were not, on their face, appropriately responsive in all material respects to the requirements of the 1934 Act and the 1934 Act Regulations (except that in each case such counsel need not express any view with respect to the financial statements, schedules and other financial and accounting information included or incorporated by reference therein or excluded therefrom including XBRL interactive data), (ii) no facts have come to such counsel’s attention that have caused such counsel to believe that each of the Registration Statement, at the Applicable Time, and the Prospectus, as of its date, appeared on its face, not to be appropriately responsive in all material respects to the requirements of the 1933 Act and the 1933 Act Regulations (except that in each case such counsel need not express any view with respect to the financial statements, schedules and other financial and accounting information included or incorporated by reference therein or excluded therefrom, including XBRL interactive data, or that part of the Registration Statement that constitutes the statement of eligibility on the Form T-1) and (iii) no facts have come to such counsel’s attention that have caused such counsel to believe that the Registration Statement, at the Applicable Time, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, or that the Prospectus, as of its date and as of the Closing Date and any Option Closing Date, as applicable, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that in each case such counsel need not express any view with respect to the financial statements, schedules and other financial and accounting information included or incorporated by reference therein or excluded therefrom, or XBRL interactive data, or that part of the Registration Statement that constitutes the statement of eligibility on the Form T-1). Such counsel shall further state that, in addition, no facts have come to such counsel’s attention that have caused such counsel to believe that the Pricing Disclosure Package, as of the Applicable Time, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that such counsel need not express any view with respect to the financial statements, schedules and other financial and accounting information included or incorporated by reference therein or excluded therefrom, including XBRL interactive data).

In addition, such statement shall confirm that the Prospectus has been filed with the Commission within the time period required by Rule 424 of the 1933 Act Regulations and any required filing of the Permitted Free Writing Prospectus pursuant to Rule 433 of the 1933 Act Regulations has been filed with the Commission within the time period required by Rule 433(d) of the 1933 Act Regulations. Such statement shall further state that assuming the accuracy of the representations and warranties of the Corporation set forth in Section 2(d) of this Agreement, the Registration Statement became effective upon filing with the Commission pursuant to Rule 462 of the 1933 Act Regulations and, pursuant to Section 309 of the 1939 Act, the Indenture has been qualified under the 1939 Act, and that based solely on such counsel’s review of the Commission’s website, no stop order suspending the effectiveness of the Registration Statement has been issued and, to such counsel’s knowledge, no proceedings for that purpose have been instituted or are pending or threatened by the Commission.

Hunton Andrews Kurth LLP may state that its opinions in paragraphs (iv), (v), (vi) and (vii) are subject to the effects of bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ rights generally and by general principles of equity (regardless of whether enforceability is considered in a proceeding in equity or at law). In addition, such counsel may state that it has relied as to certain factual matters on information obtained from public officials, officers and representatives of the Corporation and that the signatures on all documents examined by them are genuine, assumptions which such counsel have not independently verified.

The Corporation will furnish you with such conformed copies of such opinions, certificates, letters and documents as you reasonably request.

7.            Indemnification. (a)  The Corporation agrees to indemnify and hold harmless each Underwriter, its respective affiliates, officers and directors, and each person, if any, who controls any Underwriter (the “Indemnified Parties”) within the meaning of Section 15 of the 1933 Act, as follows:

In no case shall the Corporation or an Underwriter (an “indemnifying party”) be liable under this indemnity agreement with respect to any claim made against any Indemnified Party or a party indemnified pursuant to Section 7(b) hereof, as the case may be, unless the indemnifying party shall be notified in writing of the nature of the claim within a reasonable time after the assertion thereof, but failure to so notify an indemnifying party shall not relieve it from any liability which it may have otherwise than under Sections 7(a) or 7(b) hereof, as applicable. An indemnifying party shall be entitled to participate at its own expense in the defense, or, if it so elects, within a reasonable time after receipt of such notice, to assume the defense of any suit, but if it so elects to assume the defense, such defense shall be conducted by counsel chosen by it and approved by the applicable Indemnified Party or Parties or party or parties indemnified pursuant to Section 7(b) hereof in any suit so brought, which approval shall not be unreasonably withheld. In any such suit, any such indemnifed party shall have the right to employ its own counsel, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the indemnifying party and such indemnified party shall have mutually agreed to the employment of such counsel, or (ii) the named parties to any such action (including any impleaded parties) include both such indemnified party and the indemnifying party and such indemnified party shall have been advised by such counsel that a conflict of interest between the indemnifying party and such indemnified party may arise and for this reason it is not desirable for the same counsel to represent both the indemnifying party and also the indemnified party (it being understood, however, that the indemnifying party shall not, in connection with any one such action or separate but substantially similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances, be liable for the reasonable fees and expenses of more than one separate firm of attorneys for all such indemnified parties, which firm shall be designated in writing by the indemnified party). The Corporation agrees to notify you within a reasonable time of the assertion of any claim against it, any of its officers or directors or any person who controls the Corporation within the meaning of Section 15 of the 1933 Act, in connection with the sale of the Securities.

8.            Default by One or More of the Underwriters. (a) If any Underwriter shall default in its obligation to purchase the Securities which it has agreed to purchase hereunder on the Closing Date or any Option Closing Date, as applicable, you may in your discretion arrange for you or another party or other parties to purchase any or all of the Securities on the terms contained herein. If within twenty-four hours after such default by any Underwriter you do not arrange for the purchase of such Securities, then the Corporation shall be entitled to a further period of twenty-four hours within which to procure another party or other parties satisfactory to you to purchase such Securities on such terms. In the event that, within the respective prescribed periods, you notify the Corporation that you have so arranged for the purchase of such Securities, or the Corporation notifies you that it has so arranged for the purchase of such Securities, you or the Corporation shall have the right to postpone such Closing Date or any Option Closing Date, as applicable, for a period of not more than seven days, in order to effect whatever changes may thereby be made necessary in the Registration Statement, the Pricing Disclosure Package or the Prospectus, or in any other documents or arrangements, and the Corporation agrees to file promptly any amendments to the Registration Statement, the Pricing Disclosure Package or the Prospectus which may be required. The term “Underwriter” as used in this Agreement shall include any person substituted under this Section 8 with like effect as if such person had originally been a party to this Agreement with respect to such Securities.

9.            Representations and Indemnities to Survive Delivery. The respective indemnities, agreements, representations, warranties and other statements of the Corporation or its officers and of the several Underwriters set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation, or statement as to the results thereof, made by or on behalf of any Underwriter or the Corporation, or any of their respective officers or directors or any controlling person referred to in Section 7 hereof, and will survive delivery of and payment for the Securities.

10.           Reliance on Your Acts. In all dealings hereunder, the Representatives shall act on behalf of each of the Underwriters, and the Corporation shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of any Underwriter made or given by the Representatives.

11.           No Fiduciary Relationship. The Corporation acknowledges and agrees that (i) the purchase and sale of the Securities pursuant to this Agreement is an arm’s-length commercial transaction between the Corporation on the one hand, and the Underwriters on the other hand, (ii) in connection with the offering contemplated hereby and the process leading to such transaction, each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Corporation or its shareholders, creditors, employees, or any other party, (iii) no Underwriter has assumed or will assume an advisory or fiduciary responsibility in favor of the Corporation with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Corporation on other matters) and no Underwriter has any obligation to the Corporation with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (iv) the Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Corporation, and (v) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the transaction contemplated hereby and the Corporation has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

12.           Recognition of the U.S. Special Resolution Regimes.

As used in this Section 12:

“BHC Act Affiliate” has the meaning assigned to the term “affiliate” in, and shall be interpreted in accordance with, 12 U.S.C. § 1841(k).

“Covered Entity” means any of the following:

“Default Right” has the meaning assigned to that term in, and shall be interpreted in accordance with, 12 C.F.R. §§ 252.81, 47.2 or 382.1, as applicable.

“U.S. Special Resolution Regime” means each of (i) the Federal Deposit Insurance Act and the regulations promulgated thereunder and (ii) Title II of the Dodd-Frank Wall Street Reform and Consumer Protection Act and the regulations promulgated thereunder.

13.            Notices. All communications hereunder will be in writing and, if sent to the Underwriters, will be mailed or telecopied and confirmed to Barclays Capital Inc., 745 Seventh Avenue, New York, New York 10019, Attention: Syndicate Registration, Facsimile: (646) 834-8133; BofA Securities, Inc., One Bryant Park, New York, New York 10036, Attention: Syndicate Department (email: dg.ecm_execution_services@bofa.com), with a copy to ECM Legal (email: dg.ecm_legal@bofa.com); Mizuho Securities USA LLC, 1271 Avenue of the Americas, New York, New York 10020, Attention: Equity Capital Markets (email: us-ecm@mizuhogroup.com); or, if sent to the Corporation, will be mailed or telecopied and confirmed to it at 525 S. Tryon Street, Charlotte, North Carolina 28202, Attention: Nicholas J. Giaimo, Senior Vice President, Treasurer and Chief Risk Officer, Telephone: (704) 382-5125. Any such communications shall take effect upon receipt thereof.

14.            Business Day. As used herein, the term “business day” shall mean any day when the Commission’s office in Washington, D.C. is open for business.

15.            Successors. This Agreement shall inure to the benefit of and be binding upon the Underwriters and the Corporation and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the parties hereto and their respective successors and the controlling persons, officers and directors referred to in Section 7 and their respective successors, heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained; this Agreement and all conditions and provisions hereof being intended to be and being for the sole and exclusive benefit of the parties hereto and their respective successors and said controlling persons, officers and directors and their respective successors, heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Securities from any Underwriter shall be deemed to be a successor or assign by reason merely of such purchase.

16.            Counterparts; Electronic Signatures. This Agreement may be executed in two or more counterparts, each of which when so executed shall be deemed to be an original and all of which when taken together shall constitute one and the same instrument. The words “execution,” “signed,” “signature,” and words of like import in this Agreement or in any other certificate, agreement or document related to this Agreement, the Indenture or the Securities shall include images of manually executed signatures transmitted by facsimile or other electronic format (including, without limitation, “pdf”, “tif” or “jpg”) and other electronic signatures (including, without limitation, DocuSign and AdobeSign). The use of electronic signatures and electronic records (including, without limitation, any contract or other record created, generated, sent, communicated, received, or stored by electronic means) shall be of the same legal effect, validity and enforceability as a manually executed signature or use of a paper-based record-keeping system to the fullest extent permitted by applicable law, including the Federal Electronic Signatures in Global and National Commerce Act, the New York State Electronic Signatures and Records Act and any other applicable law, including, without limitation, any state law based on the Uniform Electronic Transactions Act or the Uniform Commercial Code.

17.            Applicable Law. This Agreement, and any claim, controversy or dispute arising under or related thereto, shall be governed by, and construed in accordance with, the laws of the State of New York.

If the foregoing is in accordance with your understanding, kindly sign and return to us two counterparts hereof, and upon confirmation and acceptance by the Underwriters, this Agreement and such confirmation and acceptance will become a binding agreement between the Corporation, on the one hand, and each of the Underwriters, on the other hand, in accordance with its terms.

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[Signature Page to Underwriting Agreement]

The foregoing Agreement is hereby
confirmed and accepted as of the date first above written.

[Signature Page to Underwriting Agreement]

SCHEDULE A

SCHEDULE B

PRICING DISCLOSURE PACKAGE

1)            Base Prospectus

2)            Preliminary Prospectus Supplement dated August 10, 2026

3)            Permitted Free Writing Prospectus

a)            Pricing Term Sheet attached as Schedule C hereto

SCHEDULE C

Pricing Term Sheet

Pricing Term Sheet dated August 10, 2026

Registration Statement No. 333-290475

Filed Pursuant to Rule 433

Supplementing the Preliminary

Prospectus Supplement

dated August 10, 2026

(To Prospectus dated September 23, 2025)

Duke Energy Corporation

35,000,000 Equity Units
(Initially Consisting of 35,000,000 Corporate Units)

The information in this pricing term sheet should be read together with the preliminary prospectus supplement dated August 10, 2026 (the “Preliminary Prospectus Supplement”), including the documents incorporated by reference therein, and the accompanying base prospectus dated September 23, 2025, each filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (Registration Statement No. 333-290475). Terms used but not defined herein have the meanings given to them in the Preliminary Prospectus Supplement.

The Company has filed a shelf-registration statement (including a Preliminary Prospectus Supplement dated August 10, 2026 and an accompanying prospectus dated September 23, 2025) with the Securities and Exchange Commission (the “SEC”), for the offering to which this communication relates. Before you invest, you should read the Preliminary Prospectus Supplement, the accompanying prospectus and the other documents the Company has filed with the SEC for more complete information about the Company and the offering. You may get these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, copies may be obtained from (i) Barclays Capital Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717 or by email at barclaysprospectus@broadridge.com or telephone at 1-888-603-5847; (ii) BofA Securities, Inc., NC1-022-02-25, 201 North Tryon Street, Charlotte, NC 28255-0001, Attention: Prospectus Department or by email at dg.prospectus_requests@bofa.com; or (iii) Mizuho Securities USA LLC, 1271 Avenue of the Americas, 3rd Floor, New York, NY 10020, Attention: Equity Capital Markets or by email at us-ecm@mizuhogroup.com.

This communication should be read in conjunction with the Preliminary Prospectus Supplement and the accompanying prospectus. The information in this communication supersedes the information in the Preliminary Prospectus Supplement and the accompanying prospectus to the extent inconsistent with the information in such Preliminary Prospectus Supplement and the accompanying prospectus.

ANY DISCLAIMERS OR OTHER NOTICES THAT MAY APPEAR BELOW ARE NOT APPLICABLE TO THIS COMMUNICATION AND SHOULD BE DISREGARDED. SUCH DISCLAIMERS OR OTHER NOTICES WERE AUTOMATICALLY GENERATED AS A RESULT OF THIS COMMUNICATION BEING SENT VIA BLOOMBERG OR ANOTHER EMAIL SYSTEM.

Schedule D

Amended and Restated Credit Agreement, dated as of March 18, 2022, among Duke Energy Corporation, Duke Energy Carolinas, LLC, Duke Energy Ohio, Inc., Duke Energy Indiana, LLC, Duke Energy Kentucky, Inc., Duke Energy Progress, LLC, Duke Energy Florida, LLC, and Piedmont Natural Gas Company, Inc., the Lenders party thereto, Wells Fargo Bank, National Association, as Administrative Agent and Swingline Lender and Wells Fargo Securities, LLC, as Joint Lead Arranger, Joint Bookrunner and Sustainability Structuring Agent (the “Amended and Restated Credit Agreement”).

Amendment No. 1, dated as of March 17, 2023, to Amended and Restated Credit Agreement, dated as of March 18, 2022.

Amendment No. 2, dated as of March 14, 2025, to Amended and Restated Credit Agreement, dated as of March 18, 2022.

Amendment No. 3, dated as of March 16, 2026, to Amended and Restated Credit Agreement, dated as of March 18, 2022.

Indenture dated as of June 3, 2008 (as such indenture has been amended and supplemented from time to time), between Duke Energy Corporation and The Bank of New York Mellon Trust Company, N.A. (formerly known as The Bank of New York Trust Company, N.A.), as trustee.

Schedule E

Brian D. Savoy

Scott B. Batson

Harry K. Sideris

Kelvin Henderson

Kodwo Ghartey-Tagoe

Cameron McDonald

Abigail L. Motsinger

Louis E. Renjel

Regis Repko

R. Alexander Glenn

T. Preston Gillespie

Bonnie Titone

Alexander J. “Sasha” Weintraub

Exhibit A

__, 2026

BARCLAYS CAPITAL INC.
BOFA SECURITIES, INC.
MIZUHO SECURITIES USA LLC

As Representatives of the several Underwriters

c/o          Barclays Capital Inc.

745 Seventh Avenue

New York, New York 10019

Re: Duke Energy Corporation—Lock-Up Agreement

Ladies and Gentlemen:

The undersigned understands that you, as representatives (the “Representatives”), propose to enter into an Underwriting Agreement on behalf of the several Underwriters named in Schedule A to such agreement (collectively, the “Underwriters”), with Duke Energy Corporation, a Delaware corporation (the “Corporation”), providing for the public offering of Equity Units that will include a stock purchase contract under which the holder of an Equity Unit will purchase from the Corporation shares of common stock, par value $0.001 per share, of the Corporation (the “Common Stock”).

In consideration of the agreement by the Underwriters to offer and sell the Equity Units, and other good and valuable consideration the receipt and sufficiency of which is hereby acknowledged, the undersigned agrees that, during the period beginning from the date hereof and continuing to and including the date (the “Cut-off Date”) 30 days after the date of the final prospectus supplement covering the offering of the Equity Units, the undersigned will not (i) directly or indirectly offer or sell (or grant any option or warrant to offer or sell), lend or pledge, or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Subject Shares (as defined below), whether any such swap or transaction described in clause (i) or (ii) above is to be settled by delivery of Subject Shares or such other securities, in cash or otherwise, or any options or warrants to purchase any Subject Shares, or any securities convertible into, exchangeable for or that represent the right to receive Subject Shares.

The foregoing restriction is expressly agreed to preclude the undersigned from engaging in any hedging or other transaction which is designed to or which reasonably could be expected to lead to or result in a sale or disposition of the undersigned’s Subject Shares even if such Subject Shares would be disposed of by someone other than the undersigned. Such prohibited hedging or other transactions would include without limitation any short sale or any purchase, sale or grant of any right (including without limitation any put or call option) with respect to any of the undersigned’s Subject Shares or with respect to any security that includes, relates to, or derives any significant part of its value from such Subject Shares.

The term “Subject Shares” means (i) the shares of Common Stock, whether now owned or hereafter acquired, owned directly by the undersigned (including holding as a custodian) or with respect to which the undersigned has beneficial ownership within the rules and regulations of the Commission and (ii) shares of Common Stock acquired prior to the Cut-Off Date pursuant to any employee or director compensation plan of the Corporation or pursuant to any employee or shareholder investment plan of the Corporation.

Notwithstanding the foregoing, the undersigned may transfer the Subject Shares (i) as a bona fide gift or gifts, provided that the donee or donees thereof agree(s) to be bound in writing by the restrictions set forth herein, (ii) to any member of the immediate family of the undersigned provided that the transferee or transferees agree(s) to be bound in writing by the restrictions set forth herein, (iii) to any trust or foundation, provided that the trustee of the trust or foundation agrees to be bound in writing by the restrictions set forth herein, and provided further that any such transfer shall not involve a disposition for value, (iv) to an entity controlled by the undersigned provided the transferee or transferees agree(s) to be bound in writing by the restrictions set forth herein, (v) pursuant to the laws of testamentary or intestate descent, provided that the transferee or transferees agree(s) to be bound in writing by the restrictions set forth herein, (vi) sales of Common Stock pursuant to any trading plan complying with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that has been entered into by the undersigned prior to the date of this letter or pursuant to any amendment or replacement of any such trading plan, so long as the number of shares of Common Stock subject to such original trading plan is not increased; provided that if such sales are required to be reported on Form 4 pursuant to Section 16(a) of the Exchange Act prior to the Cut-off Date, or the undersigned voluntarily effects any public filing or report regarding such sales prior to the Cut-off Date, then the undersigned shall disclose in such filing or report that such sale was made pursuant to an existing Rule 10b-5-1 trading plan, or (vii) with the prior written consent of the Representatives. For purposes of this Lock-Up Agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin. The undersigned will have at the time the undersigned acquires each of the Subject Shares, and, except as contemplated by clause (i), (ii), (iii), (iv), (v), (vi) or (vii) above, for the duration of this Lock-Up Agreement will have, good and marketable title to such Subject Shares, free and clear of all liens, encumbrances, and claims whatsoever created by the undersigned. The undersigned also agrees and consents to the entry of stop transfer instructions with the Corporation in its capacity as transfer agent and registrar against the transfer of the Subject Shares except in compliance with the foregoing restrictions and shall cause any successor transfer agent and/or registrar to agree and consent to the entry of such stop transfer instructions.

Notwithstanding the foregoing, the undersigned may not make any transfer of the Subject Shares under clauses (i), (ii), (iii) or (iv) above if any filing by any party (donor, donee, transferor or transferee) under Section 16(a) of the Exchange Act shall be required (or be made voluntarily) in connection with such transfer or distribution (other than a filing on a Form 5 made after the expiration of the 30-day period referred to above).

The undersigned acknowledges and agrees that the Underwriters have not provided any recommendation or investment advice nor have the Underwriters solicited any action from the undersigned with respect to the offering of the Equity Units and the undersigned has consulted their own legal, accounting, financial, regulatory and tax advisors to the extent deemed appropriate. The undersigned further acknowledges and agrees that, although the Representatives may be required or choose to provide certain Regulation Best Interest and Form CRS disclosures to the undersigned in connection with the offering, the Representatives and the other Underwriters are not making a recommendation to the undersigned to enter into this Lock-Up Agreement, and nothing set forth in such disclosures is intended to suggest that the Representative or any Underwriter is making such a recommendation.

The undersigned understands that the Corporation and the Underwriters are relying upon this Lock-Up Agreement in proceeding toward consummation of the offering. The undersigned further understands that this Lock-Up Agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors, and assigns.

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