As filed with the Securities and Exchange Commission on September 11, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

NETSCOUT SYSTEMS, INC.

(Exact name of registrant as specified in its charter)

310 Littleton Road, Westford, MA 01886

(Address of principal executive offices) (Zip code)

NetScout Systems, Inc. 2019 Equity Incentive Plan, as amended

NetScout Systems, Inc. Amended and Restated 2011 Employee Stock Purchase Plan, as amended

(Full Titles of the Plans)

Anil K. Singhal, President and Chief Executive Officer

NetScout Systems, Inc.

310 Littleton Road

Westford, MA 01886

(978) 614-4000

(Name and address of agent for service) (Telephone number, including area code, of agent for service)

Copies to:

Miguel J. Vega

Julia R. Boesch

Cooley LLP

500 Boylston Street

Boston, MA 02116

(617) 937-2319

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

EXPLANATORY NOTE

On September 9, 2026, the Registrant’s stockholders approved (a) the amendment of the NetScout Systems, Inc. 2019 Equity Incentive Plan (as amended, the “2019 Plan”) to, among other things, increase the number of shares of Common Stock reserved for issuance under the 2019 Plan by 3,500,000 shares, and (b) the amendment of NetScout Systems, Inc. Amended and Restated 2011 Employee Stock Purchase Plan (as amended, the “2011 ESPP” and, together with the 2019 Plan, the “Plans”) to, among other things, increase the number of shares of Common Stock reserved for issuance under the 2011 ESPP by 4,000,000 shares. Accordingly, this Registration Statement is being filed to register an additional 7,500,000 shares of Common Stock for future issuance under the Plans. The additional shares of Common Stock under the 2019 Plan are securities of the same class as other securities for which an original registration statement on Form S-8 (File No. 333-234326) was filed with the Securities and Exchange Commission (the “Commission”) on October 25, 2019, and subsequent registration statements on Form S-8 were filed with the Commission on September 14, 2020 (File No. 333-248786), on August 25, 2022 (File No. 333-267069), on September 15, 2023 (File No. 333-274543), on September 17, 2024 (File No. 333-282184) and on September 12, 2025 (File No. 333-290226) (each, an “EIP Prior Registration Statement”). The additional shares of Common Stock under the 2011 ESPP are securities of the same class as other securities for which an original registration statement on Form S-8 (File No. 333-178411) was filed with the Commission on December 9, 2011 and subsequent registration statements on Form S-8 were filed with the Commission on November 8, 2018 (File No. 333-228272) and on August 25, 2022 (File No. 333-267069) (each, an “ESPP Prior Registration Statement” and together with the EIP Prior Registration Statements, the “Prior Registration Statements”). Pursuant to General Instruction E of Form S-8, this registration statement incorporates by reference the contents of the Prior Registration Statements.

PART II

The following documents (File No. 000-26251) filed by the Registrant with the Commission are incorporated by reference into this Registration Statement (excluding any portions of such documents that have been “furnished” but not “filed” for purposes of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)):

All reports and other documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act (other than Current Reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits furnished on such form that relate to such items) on or after the date of this Registration Statement and prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be a part of this Registration Statement from the date of the filing of such reports and documents. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any subsequently filed document that also is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Westford, Commonwealth of Massachusetts, on September 11, 2026.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Anil K. Singhal and Anthony Piazza, and each or any one of them, his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his or her substitutes or substitute, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.