MSC INDUSTRIAL DIRECT CO INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934

MSC INDUSTRIAL DIRECT CO., INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Notice of 2026 Annual Meeting

and 2025 Proxy Statement

NOTICE OF 2026 ANNUAL MEETING OF SHAREHOLDERS

To the shareholders of MSC Industrial Direct Co., Inc.:

NOTICE IS HEREBY GIVEN that the 2026 Annual Meeting of Shareholders (the “Annual Meeting”) of MSC Industrial Direct Co., Inc., a New York corporation, will be held at 9:00 a.m., Eastern Time, on Wednesday, January 21, 2026 via live audio webcast atwww.virtualshareholdermeeting.com/MSM2026, for the following purposes, as more fully described in the accompanying Proxy Statement:

1. To elect the ten directors nominated by the Board of Directors;

2. To ratify the appointment of Ernst & Young LLP to serve as our independent registered public accounting firm for fiscal year 2026;

3. To approve, on an advisory basis, the compensation of our named executive officers;

4. To approve Amendment No. 1 to our Amended and Restated Associate Stock Purchase Plan to increase the number of shares available for sale thereunder by 300,000 shares of our Class A common stock and to extend the plan's term; and

5. To consider and act upon such other matters as may properly come before the Annual Meeting or any adjournment or postponement thereof.

The Board of Directors recommends that you vote “FOR” Items 1, 2, 3 and 4. The proxy holders will use their discretion to vote on other matters that may properly come before the Annual Meeting or any adjournment or postponement thereof.

Shareholders as of the close of business on November 24, 2025, the record date, are entitled to receive notice of, and to vote at, the Annual Meeting or any adjournment or postponement thereof.

The Annual Meeting will be held entirely online via live audio webcast atwww.virtualshareholdermeeting.com/MSM2026. There will not be an option to attend the Annual Meeting in person.

Shareholders as of the close of business on the record date may participate in, and submit questions and vote during, the Annual Meeting by visitingwww.virtualshareholdermeeting.com/MSM2026. To log in, you must enter the 16-digit control number included on your Notice of Internet Availability of Proxy Materials or proxy card or the instructions that you receive by e-mail. If you are a beneficial shareholder, you may contact the shareholder of record (e.g., your bank, broker or other nominee) if you have questions about obtaining your control number. If you do not have a control number, you may still access the live audio webcast of the Annual Meeting as a guest, but you will not be able to submit questions or to vote online during themeeting.

Whether or not you expect to participate in the Annual Meeting, your vote is important. To ensure your representation at the Annual Meeting, you are urged to cast your vote, as instructed in your Notice of Internet Availability of Proxy Materials or proxy card or the instructions that you receive by e-mail, as promptly as possible. If you received a copy of the proxy materials by mail, you may complete, sign, date and mail the proxy card in the envelope provided. Shareholders as of the close of business on the record date participating in the live audio webcast of the Annual Meeting may vote via the Internet during the meeting, even if they have voted via the Internet or by telephone or returned a completed proxy card. You may revoke your proxy or change your vote at any time prior to the taking of the vote at the Annual Meeting. If you participate in and vote during the Annual Meeting, your proxy will be revoked automatically and your vote during the meeting will be counted.

Shareholders are being notified of the Proxy Statement and form of proxy beginning on or about December 11, 2025.

By Order of the Board of Directors,

Neal Dongre

Senior Vice President, General Counsel andCorporate Secretary

Melville, New York

IMPORTANT: Your vote is important. Whether or not you plan to participate in the live audio webcast of the Annual Meeting, we encourage you to read this Proxy Statement and to vote your shares as soon as possible.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING OF SHAREHOLDERS TO BE HELD ON JANUARY 21, 2026:The Notice of 2026 Annual Meeting and 2025 Proxy Statement and the 2025 Annual Report to Shareholdersare available at https://investor.mscdirect.com/annual-results.

We are furnishing this Proxy Statement to you in connection with the solicitation of proxies by our Board of Directors (the “Board of Directors” or the “Board”) to be used at the 2026 Annual Meeting of Shareholders (the “Annual Meeting”), or at any adjournment or postponement thereof. This Proxy Statement describes the matters to be presented at the Annual Meeting and related information that will help you vote your shares. References in this Proxy Statement to “MSC,” the “Company,” “we,” “us,” “our” and similar terms mean MSC Industrial Direct Co., Inc.

We have elected to take advantage of the “notice and access” rule of the United States Securities and Exchange Commission (the “SEC”) that allows us to furnish proxy materials to shareholders online. We believe that electronic delivery expedites the receipt of proxy materials, while significantly lowering costs and reducing the environmental impact of printing and mailing full sets of proxy materials. As a result, on or about December 11, 2025, we mailed to our shareholders of record as of the close of business on November 24, 2025, either (i) a Notice of Internet Availability of Proxy Materials containing instructions on how to access our proxy materials online and how to request paper copies of our proxy materials or (ii) a printed set of proxy materials, which includes the Notice of 2026 Annual Meeting of Shareholders, this Proxy Statement, our 2025 Annual Report to Shareholders and a proxy card. If you received a Notice of Internet Availability of Proxy Materials by mail, you will not receive a printed copy of the proxy materials unless you specifically request one. If you hold your shares through a bank, broker or other nominee, rather than directly in your own name, your intermediary will either forward to you a printed copy of the proxy materials or provide you with instructions on how you can access the proxy materials electronically.