Ridehalgh or Ridealgh is a surname. Notable people with the surname include:
Arthur Ridehalgh (1907–1971), British lawyer and attorney general of Hong Kong George Ridehalgh (1835–1892), English businessman Judith Constance Mary Ridehalgh, later Judith Hart, British politician Liam Ridehalgh (born 1991), British footballer Mabel Ridealgh (1898–1989), British politician
See also Sagar v Ridehalgh & Sons Ltd, 1931 UK labour law case