William Pierce is the name of:

Politics

• William Pierce (politician) (1753–1789), Continental Congressman from Georgia
• William Luther Pierce (1933–2002), white nationalist and political activist
• Bud Pierce (William C. Pierce, born 1956), politician in Oregon

Sports

• Billy Pierce (Walter William Pierce, 1927–2015), American baseball player
• Bill Pierce (baseball) (William Herbert Pierce, 1890–1962), Negro leagues baseball player and manager

Other

• William Pierce (serial killer) (1931–2020), American serial killer also known as "Junior"
• William Henry Pierce (missionary) (1856–1948), Canadian missionary for the Methodist church
• William H. Pierce (1859–1939), American mortuarist
• William S. Pierce (born 1937), American surgeon and chemical engineer
• William Pierce (robber), perpetrator of the Great Gold Robbery