William Campbell or Bill Campbell may refer to:

Politicians:

• Bill Campbell (California politician)
• Bill Campbell (mayor) (b. 1953)
• Lord William Campbell (d. 1778), Governor of Nova Scotia (1766–73), the last British governor of South Carolina (1775).
• William Campbell (Canadian politician)
• William Campbell (jurist) (1758–1834), Chief Justice of the Supreme Court of Upper Canada.
• William Campbell (Lieutenant Governor of Nova Scotia)
• William Campbell (Texas politician)
• William B. Campbell (1807–1867), governor of Tennessee
• William Bennett Campbell, (b. 1943), former premier of Prince Edward Island, Canada.
• William W. Campbell (NY) (1806–1881), a U.S. Representative from New York
• William Wildman Campbell (1853–1927), a U.S. Congressman from Ohio

Others:

• Bill Campbell (baseball player) (b. 1948)
• Bill Campbell (CEO)
• Bill Campbell (comedian)
• Bill Campbell (rugby player) (b. 1961)
• Bill Campbell (sportscaster)
• Billy Campbell (b. 1959), American actor (mostly TV)
• William Campbell (Astrid member)
• William Campbell (film actor) (born 1926), American actor (mostly film)
• William Campbell (general) (1745–1781), a Continental general of the American Revolutionary War.
• William Campbell (metallographer) (b. 1876)
• William Campbell (sailor), American Civil War sailor and Medal of Honor recipient
• William Campbell (settler) in Canterbury, New Zealand
• William Campbell (soldier), American Civil War soldier and Medal of Honor recipient
• William H. Campbell (1808-1890), president of Rutgers College
• William Shears Campbell, a fictitious figure who was purported to have replaced Paul McCartney in The Beatles
• William Wallace Campbell (1862–1938), a U.S. astronomer
• William Wilfred Campbell, Canadian poet