WASHINGTON—The Federal Reserve’s lead architect of postcrisis financial regulations plans to resign this spring, giving President Donald Trump more freedom to remake the central bank and to accelerate a deregulatory agenda by putting his own appointees in charge of overseeing Wall Street.

Daniel Tarullo, a 64-year-old Fed governor and the government’s most influential overseer of the American banking system, wrote to Mr. Trump on Friday saying he would resign “on or about” April 5. The move had been expected, and will remove...