William Flynn
William, Bill or Billy Flynn may refer to:
Arts and entertainment
- Billy Flynn (Chicago) (fl. 1926), fictional lawyer from the musical Chicago
 - Bill Flynn (1948–2007), South African film and theater actor and comedian
 - Billy Flynn (musician) (born 1956), American Chicago blues guitarist
 - Billy Flynn (actor) (born 1985), American actor
 
Law and politics
- William J. Flynn (1867–1928), American director of the Bureau of Investigation
 - William S. Flynn (1885–1966), American politician; Governor of Rhode Island
 - Bill Flynn (Florida politician) (1917–1984), American politician in the Florida House of Representatives
 - Bill Flynn (New Jersey politician) (born 1938), American politician in the New Jersey General Assembly
 - Bill Flynn (Australian politician) (1951–2011), Queensland MP and leader of One Nation
 
Sports
- William Flynn (golfer) (1890–1944), American golf course architect
 - William Flynn (American football) (died 1958), American football coach
 - Bill Flynn (footballer) (1907–1991), Australian rules footballer
 - William J. Flynn (athletic director) (died 1997), American college athletics administrator
 
Others
- William Flynn (1926–2018), CEO, chairman, then chairman emeritus of Mutual of America
 - William "Billy" Flynn, responsible for the murder of Gregory Smart, the husband of Pamela Smart
 
See also
- William Flinn (1851–1924), U.S. political figure