Filed Pursuant to Rule 424(b)(3)

Registration No. 333-253114

PROSPECTUS SUPPLEMENT NO. 7

(to Prospectus dated March 30, 2021)

ADVENT TECHNOLOGIES HOLDINGS, INC.

Primary Offering Of

26,392,355 Shares of Common Stock

Secondary Offering of

23,210,601 Shares of Common Stock

4,340,278 Warrants to Purchase Common Stock

This prospectus supplement amends and supplements the prospectus dated March 30, 2021 (as supplemented or amended from time to time, the “Prospectus”), which forms a part of our Registration Statement on Form S-1 (No. 333-253114). This prospectus supplement is being filed to update and supplement the information in the Prospectus with the information contained in our Current Report on Form 8-K, filed with the Securities and Exchange Commission on June 10, 2021 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement.

The Prospectus and this prospectus supplement relate to the issuance by us of up to an aggregate of (i) 22,052,077 shares of our common stock that may be issued upon exercise of warrants to purchase common stock at an exercise price of $11.50 per share (the “public warrants”) issued by AMCI Acquisition Corp. (“AMCI”) in its initial public offering; (ii) 3,940,278 shares of our common stock that may be issued upon exercise of placement warrants at an exercise price of $11.50 per share that were originally sold to AMCI Sponsor LLC (the “Sponsor”) in a private placement consummated simultaneously with AMCI’s IPO (the “placement warrants”); and (iii) up to an aggregate of 400,000 shares of our common stock that may be issued upon the exercise of the working capital warrants at an exercise price of $11.50 per share that were issued to the Sponsor in connection with loans made by it to AMCI prior to the closing of the Business Combination (as defined below), (the “working capital warrants” and, together with the placement warrants and the public warrants, the “warrants”).

The Prospectus and this prospectus supplement also relate to the offer and sale, from time to time, by the selling securityholders named in the Prospectus (the “Selling Securityholders”), or any of their permitted transferees, of (i) up to an aggregate of 6,500,000 shares of our common stock that were issued to certain investors (collectively, the “PIPE Investors”) in a private placement in connection with the closing of the Business Combination; (ii) up to an aggregate of 12,370,323 shares of our common stock otherwise held by the Selling Securityholders; (iii) up to an aggregate of 3,940,278 shares of our common stock that may be issued upon exercise of the placement warrants held by the Selling Securityholders; (iv) up to an aggregate of 400,000 shares of our common stock that may be issued upon the exercise of the working capital warrants held by the Selling Securityholders and (v) up to an aggregate of 3,940,278 placement warrants and 400,000 working capital warrants held by the Selling Securityholders, as further described in the Prospectus. The Prospectus and this prospectus supplement also cover any additional securities that may become issuable by reason of share splits, share dividends or other similar transactions.

Our common stock and warrants are listed on Nasdaq under the symbols “ADN” and “ADNWW”, respectively. On June 9, 2021, the closing price of our common stock was $10.59 per share and the closing price of our warrants was $1.78 per share.

This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not be delivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectus supplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement.

Investing in our securities involves risks that are described in the “Risk Factors” section beginning on page 12 of the Prospectus.

Neither the SEC nor any state securities commission has approved or disapproved of the securities to be issued under the Prospectus or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is June 10, 2021.