Exhibit 99.1

 

Notice - and - access

How can I participate in the meeting?

Shareholders will not be able to attend this year’s meeting in person. It is important that you review the detailed information on how shareholders can participate in and vote at the meeting starting on page 7 of the accompanying circular. The procedures are different for registered and non-registered shareholders. You should carefully review this information well in advance of the meeting.

Only registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) will be entitled to attend, ask questions and vote at the meeting online, all in real time.

Non-registered (beneficial) shareholders who do not duly appoint themselves as proxyholder and registered guests may attend the meeting online, but will not be able to ask questions or vote at the meeting.

Registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) will be able to ask questions through a chat box in the online meeting platform or verbally over the phone using a toll-free phone number displayed during the meeting on the online meeting platform. They will not be able to vote over the phone during the live meeting – should registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) wish to vote during the meeting, they must do so using the online meeting platform.

Registered shareholders and duly appointed proxyholders participating in the meeting must remain connected to the internet at all times during the meeting in order to vote when balloting commences. It is the registered shareholder’s and duly appointed proxyholder’s responsibility to ensure internet connectivity for the duration of the meeting. Shareholders are encouraged to vote in advance using any of the methods below.

Electronic copies of the circular may be accessed online on Hydro One’s website at www.hydroone.com/AGM or under Hydro One’s profile on the System for Electronic Data Analysis and Retrieval + (SEDAR+) at www.sedarplus.com. You can also access our 2025 annual report (the annual report) containing our financial statements and related management’s discussion and analysis for the year ended December 31, 2025 in the same manner. You can also access our meeting materials online at www.proxyvote.com (enter the control number located on the voting instruction form or form of proxy). The meeting materials will remain available at www.proxyvote.com for a period of at least one year after posting on this website.

In addition to being able to quickly view or print the circular and/or annual report online at our website, shareholders can request that a paper copy of either document or both documents be sent to them by regular postal delivery, free of charge, up to one year after the date of filing on SEDAR+. Requests may be made using the methods below.

By phone:

Online:

Email:

To receive the meeting materials prior to the proxy deadline (as defined below) for the meeting and before the meeting, you should make your request before 5:00 p.m. (E.D.T.) on May 25, 2026. For requests received on or after the date of the meeting, and within one year of the circular being filed on SEDAR+, a paper copy will be mailed to you within 10 calendar days after receiving your request.

Shareholders attending the shareholders meeting (including beneficial shareholders who have properly appointed themselves as proxyholders) can only vote online. Detailed information on how shareholders can participate in and vote at the meeting starts on page 7 of the accompanying circular. This includes information on how beneficial shareholders can appoint themselves as proxyholders.

The procedures are different for registered and non-registered (beneficial) shareholders, so you should review this information carefully well in advance of the meeting. Registered guests may attend the meeting online but will not be able to ask questions or vote at the meeting.

You may also vote your shares in advance by proxy in any of the following ways. You will need the control number contained in the accompanying voting instruction form or form of proxy in order to vote.

To be valid, shareholders must return their proxies using one of the above applicable methods to Broadridge Investor Communications Corporation (Broadridge) by no later than 2:00 p.m. (E.D.T.) on June 5, 2026 (the proxy deadline) or, if the meeting is postponed or adjourned, no later than 48 hours (not including Saturdays, Sundays or holidays in Ontario) prior to the postponed or adjourned meeting. Non-registered (beneficial) shareholders should return their voting instruction form to their intermediary using one of the above methods so it is received at least one business day in advance of the proxy deadline and should consult the instructions on their voting instruction form.

Hydro One reserves the right to accept late proxies and to waive the proxy deadline, with or without notice, but is under no obligation to accept or reject any particular late proxy.

The contents of the circular and the sending thereof to the shareholders have been approved by Hydro One’s board of directors.

 

 

 

This document informs you about the meeting, as well as the governance and compensation matters at Hydro One. We have organized the document into separate sections to make it easier to find what you are looking for and to help you vote with confidence.

We pay the cost for proxy solicitation of all registered owners and beneficial owners, other than beneficial owners who object to their name and address being given to the company. These objecting beneficial owners will not receive the materials unless such objecting beneficial owners’ intermediary assumes the cost of delivery.

We are soliciting proxies mainly by mail, but you may also be contacted by phone, the internet or in person by employees of Hydro One. We may also engage solicitation agents to contact you, at a nominal cost to the company.

The date of this circular is April 27, 2026 and, unless indicated otherwise, all information in the circular is provided as of April 27, 2026 and all dollar amounts are in Canadian dollars.

All references to financial results are based on Hydro One’s financial statements, prepared in accordance with United States Generally Accepted Accounting Principles (US GAAP). References in this circular to the meeting include any postponement(s) or adjournment(s) that may occur.

Documents and websites referenced herein are not incorporated by reference into this circular, unless such incorporation by reference is explicit. References to our website address in this circular are intended to be inactive textual references only.

As set out in the notice of meeting, shareholders of Hydro One will be asked to receive or consider and, as required, vote on the following matters at the meeting:

The audited consolidated financial statements of Hydro One for the fiscal year ended December 31, 2025 and the report of the external auditors on the financial statements will be received.

The board is currently composed of 11 directors. All current directors, except for Michael Rencheck and Debbie Hutton, were elected at the company’s annual and special meeting of shareholders held on June 24, 2025. Mr. Rencheck was appointed to the board effective August 14, 2025, by the board of directors to fill the vacancy created by Timothy Hodgson’s retirement from the board on April 28, 2025. Ms. Hutton was appointed to the board effective February 19, 2026, following her nomination by the Province (defined below). Megan Telford is being nominated for election as a director in her capacity as President and CEO, with such appointment to become effective June 9, 2026, replacing David Lebeter. As a result of the retirements of Mitch Panciuk and Helga Reidel from the board, His Majesty the King in Right of Ontario (the Province) is entitled under the Governance Agreement between the company and the Province, as represented by the Minister of Energy and Mines, dated November 5, 2015 (the Governance Agreement), to nominate four candidates for election or appointment to the board. The Province has nominated Susan Wolburgh Jenah, Debbie Hutton and Perrin Beatty for election to the board.

The Province and Hydro One entered into the 2026 Waiver (defined below) in connection with the meeting. Pursuant to the 2026 Waiver, the Province acknowledged that it was nominating fewer directors than it was entitled to nominate for election at the meeting pursuant to the Governance Agreement. If, following the meeting, the Province identifies an individual as a nominee, which is accepted by Hydro One, all in accordance with the terms and conditions of the Governance Agreement, then Hydro One will appoint such individual to the board within a reasonable period.

At the meeting, shareholders will be asked to elect the 10 nominees listed in the circular (the nominated directors) in accordance with Hydro One’s Majority Voting Policy.

All directors elected will hold office until the next annual meeting of shareholders or until their successors are elected or appointed. Other details about the nominees for election as directors are provided starting on page 15.

The board recommends that you vote FOR the election to the board of each of the nominated directors.

The table below summarizes the 2025 voting results for each of the nominated directors who are standing for re-election at the 2026 meeting.

The external auditor of Hydro One is KPMG LLP (KPMG), Chartered Professional Accountants, located in Toronto, Ontario. KPMG was initially appointed as the external auditor of Hydro One on August 31, 2015. KPMG has also acted as the external auditor of Hydro One’s principal subsidiary, Hydro One Inc., since 2008. Shareholders are being asked to approve the appointment of KPMG as the external auditor of Hydro One for the ensuing year and to authorize the directors of the company to fix their remuneration.

The aggregate fees billable by KPMG to Hydro One Limited and its subsidiaries in respect of professional services for 2025 and 2024 are presented below (in Canadian dollars):

The board recommends that you vote FOR the re-appointment of KPMG as the external auditors of Hydro One, to hold office until our next annual meeting of shareholders, and to authorize the directors of Hydro One to fix their remuneration.

For additional information on our auditors and audit committee, please refer to the following sections of our annual information form for the year ended December, 31, 2025, which is available on SEDAR+ (www.sedarplus.com): “Audit Committee” and “Schedule ‘A’ – Hydro One Limited – Audit Committee Mandate”.

In accordance with Hydro One’s corporate governance guidelines, the company will hold an advisory vote on the approach to executive compensation (say on pay). The purpose of the say on pay vote is to obtain shareholder input on executive compensation at each annual meeting of shareholders.

The board believes that the shareholder say on pay vote forms an important part of the ongoing process of engagement between shareholders and the board on executive compensation.

At the meeting, shareholders will have an opportunity to vote on Hydro One’s approach to executive compensation through consideration of the following say on pay advisory resolution:

“Resolved, on an advisory basis and not to diminish the role and responsibilities of the board of directors, that the shareholders accept the approach to executive compensation disclosed in the management information circular delivered in advance of the 2026 annual meeting of shareholders of the company.”

Because your vote is advisory, it will not be binding on the board. However, the board will take into account the results of the vote when considering future executive compensation arrangements. The directors remain responsible for overseeing the company’s executive compensation practices, in accordance with applicable law, and are not relieved of this responsibility by the outcome of this advisory vote by shareholders.

The board recommends that you vote FOR approval of the advisory resolution on Hydro One’s approach to executive compensation.

For the voting results of all other matters which were voted on by shareholders at the 2025 annual and special meeting of shareholders, please refer to the report of voting results available on SEDAR+.

As permitted by applicable Canadian securities laws, Hydro One is providing shareholders with electronic access to its circular for the company’s annual meeting of shareholders and its 2025 annual report, using “notice-and-access” instead of mailing out paper copies. Electronic delivery is environmentally friendly and cost effective.

Shareholders will receive a notice of availability of proxy materials (notice) together with a form of proxy or voting instruction form. The notice provides instructions on how shareholders may access and review an electronic copy of the circular and how to request a paper copy. Shareholders who have already provided instructions on their account to receive paper copies of the circular will also receive a paper copy of the circular with a copy of the notice regarding electronic availability. The notice also provides instructions on voting at the meeting.

Proxy materials are sent to registered shareholders directly and will be sent to intermediaries to be forwarded to all non-registered (beneficial) shareholders. We pay the cost for proxy solicitation of all registered owners and beneficial owners other than beneficial owners who object to their name and address being given to the company. An objecting beneficial owner will only receive proxy materials if their intermediary assumes the cost of delivery.

As of April 27, 2026 there were 600,096,020 common shares outstanding, each carrying the right to one vote per common share.

Shareholders have the right to one vote per common share held by them on the record date for the meeting, which is April 27, 2026.

Other than the Province (defined above), any person, or an entity controlled by a person, who beneficially owns shares that represent, in the aggregate, more than 10% of the eligible votes that may be cast at the meeting, may not vote any of their shares.

As of April 27, 2026, our directors and executive officers were not aware of any person or entity who beneficially owns, directly or indirectly, or exercises control or direction over 10% or more of our outstanding common shares, other than the Province, which holds 282,412,648 common shares (representing approximately 47% of the outstanding common shares).

Under the Governance Agreement, the Province and Hydro One exchanged nomination notices and confirmed their acceptance of each other’s director nominees. The Province is also required, under the Governance Agreement between the company and His Majesty the King in Right of Ontario, as represented by the Minister of Energy and Mines, dated November 5, 2015 (the Governance Agreement), to vote in favour of the nominees identified in this circular except in the case of contested director elections and where His Majesty the King in Right of Ontario (the Province) seeks to replace the board in accordance with the Governance Agreement by withholding votes or voting for removal.

We have decided to host this year’s annual shareholder meeting as a virtual meeting. Shareholders and registered guests can attend the meeting online via a live audio webcast. The company believes conducting the meeting in a virtual fomat will maximize shareholder attendance by providing each shareholder, regardless of location, with an equal opportunity to participate in the meeting, at no additional cost.

It is anticipated that registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) attending the meeting online will be afforded substantially the same rights and opportunities to participate in the meeting as they would at an in-person meeting. Registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) will be entitled to attend, ask questions, and vote at the meeting online, all in ‘real time’. Non-registered (beneficial) shareholders who do not duly appoint themselves as proxyholders and registered guests will be able to attend the online meeting, but will not be able to participate in, ask questions or vote at the meeting.

If registered shareholders or duly appointed proxyholders are participating in the meeting online, you must remain connected to the internet at all times during the meeting in order to vote when balloting commences. It is your responsibility to ensure internet connectivity for the duration of the meeting. All shareholders are encouraged to vote in advance of the meeting at www.proxyvote.com or as described below, particularly if they are worried about their ability to remain connected to the internet for the duration of the meeting.

Registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) will be able to attend, ask questions and vote at the meeting online by using an internet connected device such as a laptop, computer, tablet or mobile phone. The online meeting platform will be supported across browsers and devices that are running the most up to date version of the applicable software plugins. If you have any doubt, you can check your system’s compatibility by visiting www.talkpoint.com/test.

Registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) will be able to participate through the online meeting platform or verbally by phone using a toll-free phone number displayed during the meeting on the online meeting platform, but they must follow the instructions below if they wish to vote at the meeting. See “How Can I Ask Questions at the Meeting”.

The steps you need to follow to attend and participate in the meeting will depend on whether you are a non-registered (beneficial) shareholder who holds common shares through a broker or other intermediary or you are a registered shareholder who holds a share certificate or statement from a direct registration system confirming your ownership of common shares. Non-registered (beneficial) shareholders who do not duly appoint themselves as proxyholders and registered guests may attend the meeting online, but will not be able to participate in, ask questions or vote at the meeting. Please read and follow the applicable instructions below carefully.

Refer to the “question period – protocol” available at www.hydroone.com/AGM to obtain more information concerning the online and in-person meeting procedures and how to ask or submit questions during the meeting, as well as other rules of conduct for the meeting.

Hydro One believes that the ability to participate in the meeting in a meaningful way, including by asking questions, is important for shareholders. It is anticipated that registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) participating in the meeting online will have substantially the same opportunity to ask proper questions as in past years when the annual meeting of shareholders was held in person or in a hybrid format.

Upon registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) logging in to the meeting online, they will have an opportunity to ask questions, make motions and raise points of order at the meeting through a chat box in the online meeting platform. Using a toll-free phone number displayed during the meeting on the online meeting platform, registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) will also be able to ask questions verbally over the phone. In order to ask questions over the phone, registered shareholders will need the 16-digit control number on their form of proxy and duly appointed proxyholders will need their Appointee Information (defined below). Questions received from registered shareholders and duly appointed proxyholders (including non-registered (beneficial) shareholders who have properly appointed themselves as proxyholders) that relate to matters of business before the meeting are expected to be addressed during the meeting, and questions that do not properly relate to matters of business before the meeting are expected to be addressed in a question and answer session following the meeting. A representative of Hydro One will respond to such questions.

The chair of the meeting will decide, at their discretion, the amount of time allocated to each question, whether it is asked online or by phone. The chair will also have the right to limit or consolidate questions to ensure as many registered shareholders and duly appointed proxyholders as possible have the opportunity to ask questions. Further, the chair may reject questions that do not relate to the business of the meeting or which are determined, in the chair’s discretion, to be inappropriate or otherwise out of order. The company does not intend to address any questions or statements that are: irrelevant to the business and affairs of the company or the business of the meeting; related to material non-public information of the company; related to personal grievances or in furtherance of personal interests; derogatory or otherwise in bad taste; repetitive of those made by another shareholder or duly appointed proxyholder; or out of order or not otherwise appropriate for the conduct of the meeting, all as determined by the chair of the meeting. Registered guests can attend and access the meeting online. However, guests (including non-registered (beneficial) shareholders who have not properly appointed themselves as proxyholders) will not be able to ask questions at the meeting.

If you have any difficulties logging in to the meeting online, please contact Broadridge’s online shareholder meeting help line using the toll-free number shown on the login page. If you are participating in the meeting online, you must remain connected to the internet at all times during the meeting in order to vote when balloting commences. It is your responsibility to ensure internet connectivity for the duration of the meeting. Note that if you lose connectivity once the meeting has commenced, there may be insufficient time to resolve your issue before ballot voting is completed.

Even if you currently plan to participate in the meeting, you should consider voting your shares in advance so that your vote will be counted in the event you experience any difficulties.

If you have been properly appointed as proxyholder for a registered or non-registered (beneficial) shareholder (or you are a non-registered (beneficial) shareholder who has appointed themselves as proxyholder), you can access and vote at the meeting during the live webcast as follows:

All shareholders must provide the Appointee Information to their appointed proxyholder exactly as they provided it to Broadridge online at www.proxyvote.com or on their voting instruction form or form of proxy in order for their proxyholder to access and vote their shares at the meeting online during the live webcast. Proxyholders who have forgotten or misplaced the applicable Appointee Information should contact the shareholder who appointed them as soon as possible. If that shareholder has forgotten or misplaced the applicable Appointee Information, they should follow the steps described under the heading “How to Vote in Advance or by Proxy” as soon as possible.

Those interested in registering to attend the meeting as a guest, can do so as set out below. Registered guests (including non-registered (beneficial) shareholders who have not properly appointed themselves as proxyholders) will be able to observe the meeting but will not otherwise be able to participate, ask questions or vote. If you wish to contact the chair of the board or any member of the board please see page 104 for contact information. Please read and follow the instructions below carefully.

Providing voting instructions online at www.proxyvote.com or by telephone or by signing and returning your proxy form or voting instruction form, authorizes David Lebeter or, failing him, Harry Taylor (the named proxyholders), the President and CEO of the company and the Chief Financial and Regulatory Officer of the company, respectively, each with full power of substitution, to vote your common shares at the meeting in accordance with your instructions. You have the right to appoint someone else to represent you at the meeting. Your proxyholder does not have to be a shareholder of the company.

We reserve the right to accept late proxies and to waive the proxy deadline with or without notice, but are under no obligation to accept or reject any particular late proxy.

You can vote in advance or appoint your proxyholder and vote by proxy using the applicable instructions set out below. How you appoint your proxyholder will depend on whether you are a non-registered (beneficial) shareholder or a registered shareholder.

The proxy form and voting instruction form stipulate that your proxyholder must vote according to the instructions you provided on your proxy form or voting instruction form, including on any ballot that may be called for at the meeting. For directors and the appointment of the external auditors, you may either vote for or withhold, and for all other matters, you may vote for or against. If you do not specify how you would like to vote, your proxyholder can vote your shares as they wish. Your proxyholder will also decide how to vote on any amendment to or variation of any item of business in the notice of meeting or on any new matters that are properly brought before the meeting, or any postponement(s) or adjournment(s).

If you properly complete and return your proxy form or voting instruction form, but do not appoint a different proxyholder and do not specify how you wish to vote, the named proxyholders will vote for you as follows:

If you are a registered shareholder, please contact Broadridge with any questions that you have about voting. You will find their contact information on page 104 of this circular. If you are a non-registered (beneficial) shareholder and you have questions about voting, please contact your broker or intermediary by following the instructions on your voting instruction form.

Votes and proxies will be counted, verified and tabulated by Broadridge in compliance with the OBCA, the by-laws of the company and applicable proxy protocols and rules. Proxies will be submitted to us and our representatives when legally necessary or appropriate, when a shareholder clearly intends to communicate with management or the board, when there is a proxy contest, or to the extent necessary to comply with applicable proxy protocols or rules of order.

We will file the voting results with securities regulators after the meeting and also post the results on our website at www.hydroone.com/AGM. The results will include details regarding the percentage of support received on each matter for which a ballot vote is held or, if no ballot vote is held, based on the votes represented by proxies validly deposited prior to the meeting.

Director nominee profiles, starting on page 16, inform you about each director nominee’s skills, experience and other important matters to consider. All but one of the director nominees are considered independent. Megan Telford is not considered independent as she serves as Chief Operating Officer of Hydro One and will assume the role of President and CEO of Hydro One effective June 9, 2026.

We expect our directors to have personal attributes and expertise that contribute to the board, to devote the time required for board and committee duties, to act with integrity, to exercise independent business judgment, and to stay informed and participate fully in board matters. The board has adopted a position description that sets out the board’s expectations for directors, which encompasses the following:

 

The information in each director nominee profile is provided as of April 27, 2026. The profiles inform you about the director nominees who are currently standing for election, including:

The skills matrix below shows each director nominee’s mix of key skills and experience in areas that are important to Hydro One’s business. In 2025, the GRC undertook a review of the skills matrix to ensure that it continues to align with and support Hydro One’s strategy and the development of a diverse board. The skills matrix is used to identify those skills for which the company will recruit when making changes to its board. The following chart outlines the key areas of skills and experience for each director nominee other than Ms. Telford: 

Description of Competencies:

On August 15, 2018, the Province passed the Hydro One Accountability Act, 2018 (HOAA). The HOAA required the company’s board of directors (the board) to establish an executive compensation framework for the board, President and CEO, and other executives. The provisions of the HOAA that required the board to establish a compensation framework for the board of directors ceased to have effect on January 1, 2023. On February 21, 2019, pursuant to the HOAA, the Management Board of Cabinet issued a directive to Hydro One (the directive) setting out certain compensation-related requirements. As specified in the directive, the maximum total compensation for the board may be adjusted annually by the lesser of the rate of the Ontario Consumer Price Index and the annual rate at which total maximum direct compensation may be adjusted for non-executive managerial employees.

The by-laws of the company provide that directors may receive remuneration for their services as determined by the board and be reimbursed for travel and other expenses properly incurred by them in attending meetings of shareholders or of the board or any committee thereof or otherwise in the performance of their duties. The directors do not receive fees for attending board or committee meetings.

The table below sets out annual directors’ compensation as at December 31, 2025. For full details of the directors compensation in 2025, please see page 26.

As part of its mandate, the GRC, comprised solely of independent directors, conducts reviews and makes appropriate recommendations to the board with respect to non-executive director compensation. Any changes to non-employee director compensation are approved by the board, following the GRC’s recommendation.

The GRC and the board determine the appropriate compensation for non-executive directors by carefully considering such key factors as:

From time to time, the GRC also retains independent compensation consultants to provide market comparisons and advice on developing appropriate non-employee director compensation programs.

Hydro One has a non-employee director Deferred Share Unit (DSU) plan that provides for director DSU awards to Hydro One directors other than the President and CEO. Directors are required to receive a minimum 60% of their annual retainer as an equity component in the form of DSUs, and they may elect to be paid up to 100% of the cash component of their compensation in the form of director DSUs. Director DSUs are notional shares that have the same value as Hydro One common shares, and directors earn additional units as dividend equivalents at the same rate as dividends paid on the company’s common shares. Director DSUs vest immediately, but directors can only redeem their DSUs for cash after they leave the board (following a one-year holding period to the extent required to comply with their share ownership requirements (SOR) post-departure). This heightened focus on deferred, equity-based compensation aligns with the compensation framework established for Hydro One executives and is intended to promote long-term decision-making and shareholder value creation.

The following table provides a summary of the compensation earned by the non-employee directors of Hydro One for the year ended December 31, 2025.

Mr. Lebeter is not included in the table as his compensation for service as Hydro One’s President and CEO is disclosed beginning on page 74. He did not receive any additional compensation for his services as a member of the board. Ms. Hutton was not a director for the year ended December 31, 2025 and has also been omitted from the table below on that basis.