William Mansfield

• William Mansfield, [1st Baron Sandhurst], British military commander, Commander-in-Chief of India, 1865–1870
• William Mansfield, 1st Viscount Sandhurst, his son, British statesman
• William Mansfield (Labour MP), British Labour politician, MP for Cleveland, 1929–1931
• Billy Mansfield, American serial killer, child molester and sex offender
• William Mansfield, suspect of the Villisca axe murders