William Lucas or Bill Lucas may refer to:

• William Lucas (Virginia politician) (1800–1877), politician and lawyer from Virginia
• William Brooks Lucas, state legislator in the United States
• William V. Lucas (1835–1921), U.S. Republican politician representing South Dakota
• William Thomas Lucas (1875–1973), farmer and Canadian federal politician
• William Lucas (bishop) (1883–1945), inaugural Bishop of Masasi
• Bill Lucas (runner) (1917–2018), British long-distance runner
• Billy Lucas (1918–1998), Welsh footballer
• William R. Lucas (1922–2025), fourth Director of the NASA Marshall Space Flight Center
• Bill Lucas (architect) (1924–2001), Australian architect
• William Lucas (actor) (1925–2016), British film and television actor
• William Lucas (Michigan politician) (1928–2022), Wayne County executive and 1986 Michigan gubernatorial candidate
• Bill Lucas (baseball) (1936–1979), American baseball executive
• Bill Lucas (rower) (born 1987), British rower
• Bill Lucas (academic) (born 1956), social entrepreneur, author, researcher and motivational speaker
• William Brooks Lucas, state legislature from Mississippi
• Bill Lucas (rugby league), Australian rugby league player