William Harcourt may refer to:
- William Vernon Harcourt (scientist)
- William Vernon Harcourt (politician)
- William Harcourt (martyr), Catholic martyr, victim of the Titus Oates plot
- William Harcourt, villain in the film Alien Nation (named for the people above)
- William Harcourt, 3rd Earl Harcourt, English nobleman and soldier
- William Harcourt (MP for Berkshire), in 1401, MP for Berkshire (UK Parliament constituency)