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, Member of British four-piece girl group Little Mix See also Thirlwall Castle, Northumberland, England Thelwall Thelwell