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