Longeveron Inc.

As filed with the Securities and Exchange Commission on April 10, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Longeveron Inc.

(Exact name of registrant as specified in its charter)

1951 NW 7 th Avenue, Suite 520

Miami, Florida 33136

Telephone: (305) 909-0840

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Stephen Willard

Chief Executive Officer

Longeveron Inc.

1951 NW 7 th Avenue, Suite 520

Miami, Florida 33136

Telephone: (305) 909-0840

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

Copies to:

Jennifer Minter, Esq.

Adam Wicks, Esq.

Buchanan Ingersoll & Rooney PC

Union Trust Building

501 Grant Street, Suite 200

Pittsburgh, PA 15219

Telephone: (412) 562-8800

Approximate date of commencement of proposed sale to the public: From time to time after this registration statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933 check the following box:☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

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.☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until this Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. The selling stockholders may not sell these securities pursuant to this prospectus until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Subject to Completion, Dated April 10, 2026

PRELIMINARY PROSPECTUS

30,865,385 Shares of Class A Common Stock

This prospectus relates to the re-sale or other disposition from time to time by certain selling stockholders identified herein (each, a “Selling Stockholder” and, together, the “Selling Stockholders”) or their pledgees, assignees, distributees and successors-in-interest, from time to time, of up to 30,865,385 shares of our Class A Common Stock, par value $0.001 per share (“Class A common stock”). Of the shares of Class A common stock being registered for resale hereunder: (i) 6,013,384 shares were issued to certain of the Selling Stockholders upon the closing of the private placement contemplated by a Purchase Agreement executed March 10, 2026 (the “Purchase Agreement”), (ii) 22,832,770 shares are issuable to certain of the Selling Stockholders upon conversion of up to 11,873.04 shares of Series A Non-Voting Preferred Stock, par value $0.001 per share (“Series A preferred stock”) issued to certain Selling Stockholders upon the closing of the private placement contemplated by the Purchase Agreement, and (iii) 2,019,231 shares are issuable to designees (or their assignees) of the placement agent upon the exercise of placement agent warrants to purchase shares of our Class A common stock that were issued in accordance with the engagement agreement executed as of June 11, 2025, as amended on August 3, 2025 and December 12, 2025 upon the closing of the private placement (the “PA Warrants”).

The PA Warrants are initially exercisable at an exercise price of $0.65 per share of Class A common stock. We are registering the offer and sale of Class A common stock on behalf of the Selling Stockholders to satisfy certain registration rights that we have granted to the Selling Stockholders.

Each Selling Stockholder may, from time to time, sell, transfer, or otherwise dispose of any or all of the Class A common stock on any stock exchange, market, or trading facility on which shares of our Class A common stock are traded or in private transactions. These dispositions may be at fixed prices, at prevailing market prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale, or at negotiated prices. The Selling Stockholders will bear all commissions and discounts, if any, attributable to the sales of Class A common stock. We will bear all other costs, expenses, and fees in connection with the registration of the Class A common stock. See “Plan of Distribution” section of this prospectus.

We are not offering any shares of our Class A common stock for sale under this prospectus. We will not receive any of the proceeds from the sale or other disposition of our Class A common stock by the Selling Stockholders. However, we may receive proceeds of up to approximately $1,312,500 if all of the PA Warrants covered by this prospectus are exercised for cash, based on the per share exercise price of the PA Warrants held by the Selling Stockholders.

Our Class A common stock is traded on the NASDAQ Capital Market under the symbol “LGVN”. On April 9, 2026, the last reported sale price for our Class A common stock as reported on the NASDAQ Capital Market was $1.11 per share.

Investing in our securities involves a high degree of risk. Before making any investment in these securities, you should consider carefully the risks and uncertainties in the “Risk Factors” section of this prospectus and in the other documents that are incorporated by reference.

Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is , 2026

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