Captain William Carrall Hilborn (whose middle and last names are variously spelled Carroll and Hillborn) (5 July 1898 – 26 August 1918) was a World War I Canadian flying ace. He was raised as a western Canadian pioneer. He undertook his own aviation education in his eagerness to join the Royal Flying Corps. He overcame physical problems and a tendency toward airsickness to become a wingman to famed Canadian ace William George Barker. After scoring seven victories in Italy, Hilborn died on 26 August 1918, of injuries received in a flying accident.