rules footballer and coach in the VFL Jack Clement (1931–2013), American singer-songwriter, record producer Jack Cock (1893–1966), English footballer Jack E. Conger (1921–2006), American Marine flying ace during World War II Jack Kent Cooke (1912–1997), Canadian entrepreneur Jack Coombs (1882–1957), Major League Baseball pitcher Jack Cork (born 1989), English footballer Jack Crawford (disambiguation), multiple people Jack Crisp (born 1993), Australian rules football player Jack Cronin (1874–1929), American Major League Baseball pitcher Jack Cronin (American football) (1903–1993), American football player Jack Cust (born 1979), American former baseball player Jack Daly (politician) (1915–1988), Irish politician Jack Daniels (disambiguation), multiple people Jack Dann (born 1945), American writer Jack Dee (born 1961), English stand-up comedian, actor, and writer Jack DeJohnette (born 1942), American jazz drummer, pianist, and composer Jack Del Rio (born 1963), American football coach Jack Dempsey (disambiguation), multiple people Jack Dickin (1899–1966), British Olympic swimmer Jack Doan (born 1972) American professional wrestling referee Jack Dorsey (born 1976), American technology entrepreneur, co-founder and CEO of Twitter Jack Douglass (born 1988), American YouTube comedian of "jacksfilms" fame Jack Driscoll (American football) (born 1997), American football player Jack Dromey (born 1948), British Labour Party politician and trade unionist Jack Dugger (1923–1988), American football player Jack Easterby (born 1982 or 1983), American football executive Jack Dyer (1913–2003), Australian rules football player and coach, broadcaster and journalist Jack Eichel (born 1996), American National Hockey League player Jack Eisner (born 1947), Israeli basketball player Jack Elam (1920–2003), American actor Jack Elder (politician) (born 1949), New Zealand former politician Jack Ellena (1931–2012), American football player Jack Elway (1931–2001), American football player and head coach Jack Ely (1943–2015), American guitarist and singer Jack Endino (born 1964), producer and musician based in Seattle Jack Evans (disambiguation), multiple people Jack Faber (1903–1994), American microbiologist and college football and lacrosse coach Jack Falahee (born 1989), American actor Jack Fellure (born 1931), American perennial political candidate and retired engineer Jack Fingleton (1908–1981), Australian cricketer Jack Finney (1911–1995), American author Jack Flaherty (disambiguation), multiple people Jack Fleck (1921–2014), American professional golfer Jack Foley (disambiguation), multiple people Jack Fox (disambiguation), multiple people Jack Fultz (born 1948), American retired long-distance runner Joaquín "Jack" García (born 1952), Cuban-American FBI agent Jack Garfinkel (1918–2013), American basketball player Jack Givens (born 1956), American retired collegiate and professional basketball player Jack Glasscock (1857–1947), American Major League Baseball player Jack Gilinsky (born 1996), member of the American pop-rap duo Jack & Jack