Michael Dillon was a British physician and the first trans man to undergo phalloplasty, or the surgical construction of a penis. He also is thought to be the first person to undergo testosterone therapy to begin his transition.

Dillon became a doctor and eventually served as a naval doctor. However, the press discovered that Dillon was not born male, and the attention caused him to flee to India. There, he took vows to become a monk in a Buddhist monastery.