CLYYF Celyad SA (CE)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the Month of April 2023

Commission File Number: 001-37452

CELYAD ONCOLOGY SA

(Translation of registrant’s name into English)

Rue Edouard Belin 2

1435 Mont-Saint-Guibert, Belgium

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F  ☒                Form 40-F  ☐

Celyad Oncology SA

On April 24, 2023, Celyad Oncology SA (the “Company”) issued a press release announcing that it had received a letter (the “Bid Price Notice”) on April 19, 2023 from The Nasdaq Stock Market informing the Company that the minimum closing bid price per share of its American Depositary Shares representing ordinary shares (“ADSs”) was below $1.00 for a period of 30 consecutive business days, and that the Company did not meet the minimum bid price requirement set forth in Nasdaq Listing Rule 5450(a)(1) (the “Minimum Bid Price Requirement”).

The Bid Price Notice has no immediate effect on the listing of the Company’s ADSs on the Nasdaq Global Market. In accordance with Nasdaq Listing Rule 5810(c)(3)(A), the Company has 180 calendar days, or until October 16, 2023, to regain compliance with the Minimum Bid Price Requirement.

A copy of the Company’s press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

The information contained in this Current Report on Form 6-K, including Exhibit 99.1, is hereby incorporated by reference into the Company’s Registration Statements on Forms F-3 (File No. 333-248464) and S-8 (File No. 333-220737).

EXHIBITS