Thirlwall is a surname. Notable people with the surname include:
Anthony Thirlwall (born 1941), Professor of Applied Economics at the University of KentThirlwall's Law, a law of economicsConnop Thirlwall (1797–1875), English clergyman and historian, Bishop of Saint David'sThirlwall Prize, awarded at Cambridge UniversityJade Thirlwall, Member of British four-piece girl group Little Mix