Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the use in this Amendment No. 1 to Registration Statement on Form S-1 (No. 333-257655) of our report dated April 27, 2021 relating to the financial statements of Rallybio Holdings, LLC. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ Deloitte & Touche LLP

Hartford, Connecticut

July 22, 2021