Ernest Ropiequet "Jack" Hilgard (July 25, 1904 – October 22, 2001) was an American psychologist and professor at Stanford University. He became famous in the 1950s for his research on hypnosis, especially with regard to pain control. Along with André Muller Weitzenhoffer, Hilgard developed the Stanford Hypnotic Susceptibility Scales. A Review of General Psychology survey, published in 2002, ranked Hilgard as the 29th most cited psychologist of the 20th century.