William Kidd (1645–1701) was a Scottish sailor and pirate commonly known as Captain Kidd

William, Bill or Billy Kidd may also refer to:

• William Kidd (painter) (1796–1863), Scottish painter
• Billy Kidd (footballer) (1908–1978), English footballer
• William Matthew Kidd (1918–1998), United States federal judge
• Billy Kidd (born 1943), American ski racer
• Bill Kidd (American politician) (born 1952), member of the Missouri House of Representatives
• Bill Kidd (born 1956), Scottish National Party politician
• Billy Kidd (American football) (born 1959), American football center
• William Kidd (composer) (fl. 1987–2012), American musician, orchestrator, and composer