William Farrell

• William Farrell (architect), Irish architect
• William Farrell (diver), American Olympic diver
• William Farrell, Irish-Canadian businessman and a founder of the British Columbia Telephone Company
• Willie Farrell, Irish politician
• Bill Farrell (baseball), baseball player
• Bill Farrell (singer), American singer in the 1940s–1950s
• Billy Farrell (footballer), League of Ireland player