Thirlwall is a surname. Notable people with the surname include:
Anthony Thirlwall (born 1941), Professor of Applied Economics at the University of Kent Thirlwall's Law, a law of economics Connop Thirlwall (1797–1875), English clergyman and historian, Bishop of Saint David's Thirlwall Prize, awarded at Cambridge University Jade Thirlwall (born 1992), an English singer William Thirlwall, English MP
See also Thirlwall Castle, Northumberland, England Thelwall Thelwell