J Jill : Proxy Statement – April 12, 2024

4 Batterymarch Park

Quincy Massachusetts,

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD JUNE 6, 2024

To the Stockholders of J.Jill, Inc.:

Notice is hereby given that the Annual Meeting of Stockholders of J.Jill, Inc. (the "Company," "J.Jill" or "we") is to be held on Thursday, June 6, 2024 at 8:00 AM Eastern, to be held online at https://web.lumiagm.com/

298043967 (the "Annual Meeting"). The Annual Meeting is called for the following purposes:

1. To elect one director to our Board of Directors (the "Board of Directors"), to serve as Class I director for a term of three years expiring at the Annual Meeting of Stockholders to be held in 2027 and until such director's successor has been duly elected and qualified;
2. To ratify the appointment of Grant Thornton LLP ("Grant Thornton") as our independent registered public accounting firm for the current fiscal year ending February 1, 2025; and
3. To consider and take action upon such other matters as may properly come before the meeting or any adjournment or postponement thereof.

These matters are more fully described in the Proxy Statement accompanying this Notice.

If you were a stockholder of record of J.Jill, Inc. common stock as of the close of business on April 9, 2024, you are entitled to receive this Notice and vote at the Annual Meeting and any adjournments or postponements thereof, provided that our Board of Directors may fix a new record date for an adjourned meeting. Our stock transfer books will not be closed. A list of the stockholders entitled to vote at the Annual Meeting may be examined at our principal executive offices in Quincy, Massachusetts during ordinary business hours or on a reasonably accessible electronic network as provided by applicable law in the 10-day period preceding the meeting for any purposes related to the meeting.

We are pleased to take advantage of the Securities and Exchange Commission (the "SEC") rules that allow us to furnish these proxy materials (including an electronic Proxy Card for the meeting) and our 2023 Annual Report to Stockholders (including our Annual Report on Form 10-K for the fiscal year ended February 3, 2024 ("Fiscal Year 2023")) to our stockholders via the Internet. On or about April 25, 2024, we will mail to our stockholders a Notice of Internet Availability of Proxy Materials containing instructions on how to access our Proxy Statement and 2023 Annual Report to Stockholders and how to vote. We believe that posting these materials on the Internet enables us to provide our stockholders with the information they need to vote more quickly, while lowering the cost and reducing the environmental impact of printing and delivering annual meeting materials.

You are cordially invited to attend the Annual Meeting, which will be conducted in a virtual-only format via a live audio webcast. We believe that this virtual format facilitates stockholder attendance, provides all stockholders a consistent experience, and allows for participation regardless of location. In order to be admitted

i

to the virtual meeting website, you will need the 11-digit control number that accompanies your proxy materials and type the password "jjill2024" to log in to the meeting. The Annual Meeting will begin promptly at 8:00 AM Eastern. We encourage you to access the meeting 15 minutes prior to the start time (at 7:45 AM Eastern) allowing ample time to log in to the meeting webcast and test your computer audio system. If you encounter any difficulty accessing the Annual Meeting, please visit https:// go.lumiglobal.com/faq for assistance.

Whether or not you expect to attend virtually, our Board of Directors respectfully requests that you vote your shares of common stock in the manner described in the Proxy Statement. You may revoke your proxy in the manner described in the Proxy Statement at any time before it has been voted at the Annual Meeting.

By Order of the Board of Directors of J.Jill, Inc.,

Claire Spofford

Chief Executive Officer, President and Director

Quincy, Massachusetts

Dated: April 12, 2024

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING TO BE HELD ON THURSDAY, JUNE 6, 2024 VIA AUDIO WEBCAST ONLY: J.Jill, Inc.'s Proxy Statement and Annual Report on Form 10-K for Fiscal Year 2023 are also available at www.astproxyportal.com/ast/JJill.

ii

iii

J.JILL, INC.

PROXY STATEMENT

ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD JUNE 6, 2024

INFORMATION CONCERNING SOLICITATION AND VOTING

This Proxy Statement is furnished to the holders of our common stock in connection with the solicitation of proxies on behalf of our Board of Directors for use at the Annual Meeting or for use at any adjournment or postponement thereof, for the purposes set forth herein and in the accompanying Notice of Annual Meeting of Stockholders. The Annual Meeting will be held on Thursday, June 6, 2024 at 8:00 AM Eastern online at https://web.lumiagm.com/298043967. Only stockholders of record at the close of business on April 9, 2024 are entitled to notice of and to vote at our Annual Meeting.

The Annual Meeting will be conducted in a virtual-only format via live audio webcast. Stockholders who attend the Annual Meeting will have an opportunity to vote and to submit written questions electronically at the Annual Meeting. Stockholders can attend the Annual Meeting by visiting https://web.lumiagm.com/298043967. In order to be admitted to the virtual meeting website, you will need to use the unique 11-digit control number previously provided with proxy materials and type the password "jjill2024" to log in to the meeting. The Annual Meeting will begin promptly at 8:00 AM Eastern. We encourage you to access the meeting 15 minutes prior to the start time, allowing ample time to log in to the meeting webcast and test your computer audio system. If you encounter any difficulty accessing the Annual Meeting, please visit https://go.lumiglobal.com/faq for assistance.

In accordance with the rules of the SEC, we are furnishing proxy materials, including the Notice, this Proxy Statement, our 2023 Annual Report to Stockholders, including financial statements, and a Proxy Card for the Annual Meeting, by providing access to them on the Internet to save printing costs and reduce impact on the environment. These materials were first available on the Internet on April 12, 2024. On or about April 25, 2024 we will mail a Notice of Internet Availability of Proxy Materials to our stockholders of record and beneficial owners as of April 9, 2024, the record date for the Annual Meeting. This Proxy Statement and the Notice of Internet Availability of Proxy Materials contain instructions for accessing and reviewing our proxy materials on the Internet and for voting by proxy over the Internet. You will need to obtain your own Internet access if you choose to access the proxy materials and/or vote over the Internet. If you prefer to receive printed copies of our proxy materials, the Notice of Internet Availability of Proxy Materials contains instructions on how to request the materials by mail. You will not receive printed copies of the proxy materials unless you request them. If you elect to receive the materials by mail, you may also vote by proxy on the Proxy Card or Voter Instruction Card that you will receive in response to your request.

Each holder of our common stock is entitled to one vote for each share held as of the record date with respect to all matters that may be considered at the Annual Meeting. Stockholder votes will be tabulated by persons appointed by our Board of Directors to act as inspectors of election for the Annual Meeting.

We bear the expense of soliciting proxies. Our directors, officers, or employees may also solicit proxies personally or by telephone, telegram, facsimile, or other means of communication. We do not intend to pay additional compensation for doing so. In addition, we might reimburse banks, brokerage firms, and other custodians, nominees, and fiduciaries representing beneficial owners of our common stock, for their expenses in forwarding soliciting materials to those beneficial owners.

1

QUESTIONS AND ANSWERS ABOUT THE 2024 ANNUAL MEETING

1. Why am I receiving these proxy materials?

1. We are furnishing you these proxy materials in connection with the solicitation of proxies on behalf of our Board of Directors for use at the Annual Meeting. This Proxy Statement includes information that we are required to provide under the SEC rules and is designed to assist you in voting your shares.

Proxies in proper form received by us at or before the time of the Annual Meeting will be voted as specified. Stockholders may specify their choices by marking the appropriate boxes on their Proxy Card. If a Proxy Card is dated, signed and returned without specifying choices, the proxies will be voted in accordance with the recommendations of our Board of Directors set forth in this Proxy Statement, and, in their discretion, upon such other business as may properly come before the Annual Meeting. Business transacted at the Annual Meeting will be confined to the purposes stated in the Notice of Annual Meeting. Shares of our common stock, par value $0.01 per share, cannot be voted at the Annual Meeting unless the holder attends the Annual Meeting or is represented by proxy.

1. Who may vote at the Annual Meeting?

1. Our Board of Directors set April 9, 2024 as the record date for the Annual Meeting. If you owned shares of our common stock at the close of business on April 9, 2024, you may attend and vote at the Annual Meeting. On all matters to be voted on, each stockholder is entitled to one vote for each share of common stock held by such stockholder. As of April 9, 2024, there were 10,747,847 shares of our common stock outstanding and entitled to vote at the Annual Meeting.

1. How do I attend the Annual Meeting?

1. The Annual Meeting will begin promptly at 8:00 AM Eastern. Online check-in will begin 15 minutes prior to the start of the Annual Meeting to allow ample time to log in to the meeting webcast and test your computer audio system.

You may attend the Annual meeting and vote your shares by visiting https://web.lumiagm.com/298043967. In order to be admitted to the virtual meeting website, you will need to use the unique 11-digit control number previously provided with proxy materials and type the password "jjill2024" to log in to the meeting. If you encounter any difficulty accessing the Annual Meeting, please visit https://go.lumiglobal.com/faq for assistance.

1. What is the difference between holding shares as a stockholder of record and as a beneficial owner?

1. If your shares are registered directly in your name with our transfer agent, Equiniti Trust Company, LLC (formerly known as American Stock Transfer & Trust Company, LLC), you are considered, with respect to those shares, a stockholder of record. As a stockholder of record, you have the right to vote electronically at the Annual Meeting.

If your shares are held in a brokerage account or by another nominee or trustee, you are considered the beneficial owner of shares held in street name. In that case, the Notice of Internet Availability of Proxy Materials or proxy materials have been forwarded to you by your broker, bank or other holder of record who is considered, with respect to those shares, the stockholder of record. As the beneficial owner, you have the right to direct your broker, bank or other holder of record on how to vote your shares by using the voting instructions included in the Notice of Internet Availability or proxy materials.

2

1. What is the quorum requirement for the Annual Meeting?

1. Holders of a majority of the voting power of all of our outstanding shares of stock entitled to vote at the meeting must be present in person (virtually) or represented by proxy at the Annual Meeting in order for us to hold the Annual Meeting and conduct business. This is called a quorum. Your shares will be counted as present at the Annual Meeting if you:
2. • Are present virtually and entitled to vote electronically at the Annual Meeting; or
   • Properly submitted a Proxy Card or Voter Instruction Card.

If you are attending the Annual Meeting or represented by proxy, but withhold your vote or abstain from voting on any or all proposals, your shares are still counted as present and entitled to vote. Each of the proposals listed in this Proxy Statement identifies the votes needed to approve the proposed action.

1. What proposals will be voted on at the Annual Meeting?

1. The two proposals to be voted on at the Annual Meeting are as follows:
2. 1. To elect one director to our Board of Directors, to serve as Class I director for a term of three years expiring at the Annual Meeting of Stockholders to be held in 2027 and until such director's successor has been duly elected and qualified; and
   2. To ratify the appointment of Grant Thornton as our independent registered public accounting firm for the fiscal year ending February 1, 2025.

We will also consider any other business that properly comes before the Annual Meeting. As of the record date, we are not aware of any other matters to be submitted for consideration at the Annual Meeting. If any other matters are properly brought before the Annual Meeting, the proxy named in the Proxy Card or Voter Instruction Card will vote the shares it represents using its best judgment.

1. What is the vote required for each proposal and what are my voting choices?

1. With respect to Proposal 1, the election of directors, you may vote FOR or WITHHOLD. A plurality of the votes cast is required to be elected as a director. A "plurality of the votes cast" means that the director nominee will be elected if she receives a greater number of votes cast "FOR" her election than "WITHHOLD" votes. If you WITHHOLD from voting on Proposal 1, the withheld vote will have no effect on the outcome of the vote (only because the outcome is determined by the number of affirmative votes for each director).

With respect to Proposal 2, you may vote FOR, AGAINST or ABSTAIN, and the vote required is the affirmative vote of a majority of the voting power of shares of stock present virtually or represented by proxy at the Annual Meeting and entitled to vote thereon. If you ABSTAIN from voting on Proposal 2, the abstention will have the same effect as an AGAINST vote.

1. How does our Board of Directors recommend that I vote?

1. Our Board of Directors recommends that you vote:
2. 1. FOR the election of the director nominee named in this Proxy Statement; and
   2. FOR the ratification of the appointment of Grant Thornton as our independent registered public accounting firm for the fiscal year ending February 1, 2025.

3

1. What is the effect of a broker non-vote?

1. Brokers or other nominees who hold shares for a beneficial owner have the discretion to vote on routine proposals when they have not received voting instructions from the beneficial owner at least 10 days prior to the Annual Meeting. A broker non-vote occurs when a broker or other nominee does not receive instructions from the beneficial owner regarding how to vote on a particular proposal and does not have the discretion to direct the voting of the shares. Broker non-votes will be counted for purposes of calculating whether a quorum is present virtually at the Annual Meeting but will not be counted for purposes of determining the number of votes cast with respect to Proposal 1. Accordingly, a broker non-vote will not impact our ability to obtain a quorum or the outcome of voting on Proposal 1. Because brokers may exercise discretion to vote on Proposal 2, we do not anticipate any broker non-votes with regard to this proposal. If you hold shares in street name and do not vote on Proposal 1, your shares will not be voted in respect of Proposal 1, and will be counted as broker non-votes.

1. Can I access these proxy materials on the Internet?

1. Yes. The Notice of Annual Meeting, Proxy Statement, and 2023 Annual Report to Stockholders (including the Annual Report on Form 10-K for Fiscal Year 2023) will be available for viewing, printing, and downloading at www.astproxyportal.com/ast/JJill. They are also available under the Investor Relations- Financial Information-SECFilings section of our website at www.jjill.com and through the SEC's EDGAR system at http://www.sec.gov. All materials will remain posted on www.astproxyportal.com/ast/JJill at least until the conclusion of the Annual Meeting.

1. How may I vote my shares electronically at the Annual Meeting?

1. If your shares are registered directly in your name with our transfer agent, Equiniti Trust Company, LLC (formerly known as American Stock Transfer & Trust Company, LLC), you are considered, with respect to those shares, the stockholder of record. As the stockholder of record, you have the right to vote electronically at the Annual Meeting. If your shares are held in a brokerage account or by another nominee or trustee, you are considered the beneficial owner of shares held in street name. As the beneficial owner, you are also invited to attend the Annual Meeting. Because a beneficial owner is not the stockholder of record, you may not vote these shares electronically at the Annual Meeting unless you obtain a "legal proxy" from the broker, nominee, or trustee that holds your shares, giving you the right to vote the shares at the Annual Meeting. Please contact your broker, nominee or trustee if you wish to obtain such a "legal proxy."

1. How can I vote my shares without attending the Annual Meeting?

1. If your shares are held by a broker, bank or other nominee, they should send you instructions that you must follow in order to have your shares voted. If you hold shares in your own name, you may vote by proxy in any one of the following ways:
2. • Via the Internet by following the instructions provided in the Notice of Internet Availability; or
   • By requesting that printed copies of the proxy materials be mailed to you pursuant to the instructions provided in the Notice of Internet Availability and completing, dating, signing and returning the Proxy Card that you receive in response to your request.

Even if you plan to attend the Annual Meeting, we encourage you to vote in advance by Internet or mail so that your vote will be counted if you later decide not to attend the Annual Meeting.

The Internet voting procedures are designed to authenticate stockholders' identities by use of a control number to allow stockholders to vote their shares and to confirm that stockholders' instructions have been properly recorded. Voting via the Internet must be completed by 11:59 PM Eastern on June 5, 2024. Of course, as described in the immediately preceding question and answer, you can always attend the Annual Meeting and

4

vote your shares electronically. If you submit or return a Proxy Card without giving specific voting instructions, your shares will be voted as recommended by our Board of Directors, as permitted by law.

1. How can I change my vote after submitting it?

1. If you are a stockholder of record, you can revoke your proxy before your shares are voted at the Annual Meeting by:
2. • Filing a written notice of revocation bearing a later date than the proxy with our Secretary and General Counsel at 4 Batterymarch Park, Quincy, Massachusetts 02169 at or before the taking of the vote at the Annual Meeting;
   • Duly executing a later-dated proxy relating to the same shares and delivering it to our Secretary and General Counsel at 4 Batterymarch Park, Quincy, Massachusetts 02169 at or before the taking of the vote at the Annual Meeting;
   • Attending the Annual Meeting and voting electronically (although attendance at the Annual Meeting will not in and of itself constitute a revocation of a proxy); or
   • If you voted via the Internet, voting again by the same means prior to 11:59 PM Eastern on June 5, 2024 (your latest Internet vote, as applicable, will be counted and all earlier votes will be disregarded).

If you are a beneficial owner of shares, you may submit new voting instructions by contacting your bank, broker, or other holder of record. You may also vote electronically at the Annual Meeting if you obtain a legal proxy from them.

1. How can I submit questions in the Annual Meeting?

1. You are encouraged to submit your questions during the Annual Meeting athttps://web.lumiagm.com/ 298043967, by using your unique 11-digit control number previously provided with proxy materials and type the password "jjill2024" to log in.

We reserve the right to exclude questions regarding topics that are not pertinent to meeting matters or company business. If we receive substantially similar questions, we may group questions together and provide a single response to avoid repetition. We may decide in our sole discretion whether to address a question during the Annual Meeting or to address a question at a later date, either directly with the party asking the question or on our Investor Relations webpage. If you encounter any difficulty submitting your questions or accessing the Annual Meeting, please visit https://go.lumiglobal.com/faq for assistance.

1. Is TowerBrook entitled to designate any director nominees for election to our Board of Directors?

1. Under the Stockholders Agreement, dated as of March 14, 2017 (the "Stockholders Agreement"), TI IV JJill Holdings, LP ("TI IV"), an affiliate of TowerBrook Capital Partners L.P. ("TowerBrook"), based on its beneficial ownership of 61.4% of our outstanding common stock taking into account Towerbrook's warrants exercisable for shares of our common stock, as of April 9, 2024, has the right to designate as nominees (the "TowerBrook Nominees") a majority of director nominees for election to our Board of Directors. Towerbrook's ownership percentage of our common stock, without taking into account Towerbrook's warrants exercisable for shares of our common stock, is 49.5%.

1. Where can I find the voting results of the Annual Meeting?

1. We will announce the preliminary voting results at the Annual Meeting. We will publish the results in a Current Report on Form 8-K filed with the SEC within four business days of the Annual Meeting. If the official results are not available at that time, we will provide preliminary voting results in the Current Report on Form 8-K and will provide the final results in an amendment to the Current Report on Form 8-K as soon as they become available.

5

1. For how long can I access the proxy materials on the Internet?

1. The Notice of Annual Meeting, Proxy Statement, 2023 Annual Report to Stockholders, and Annual Report on Form 10-K for Fiscal Year 2023 will remain posted at www.astproxyportal.com/ast/JJill until the conclusion of the Annual Meeting, and also are and will remain available, free of charge, in PDF and HTML format under the Investor Relations-Financial Information-SECFilings section of our website at www.jjill.com.

6