(born 1994), American professional baseball player Jack Ladyman (born 1947), American politician Jack Lambert (disambiguation), multiple people Jack Larsen (born 1995), American baseball player Jack Larson (1928–2015), American actor Jack Layton (1950–2011), Canadian politician Jack Leathersich (born 1990), American baseball player Jack Le Brocq (born 1992), Australian racing driver Jack Lemmon (1925–2001), American actor Jack Lew (born 1955), American government administrator, attorney, and 76th United States Secretary of the Treasury Jack Lindsay (1900–1990), Australian-born British writer and poet Jack Lindsay (footballer) (1921–2006), Scottish footballer Jack London (disambiguation), multiple people Jack Lord (1920–1998), American actor Jack Lowden (born 1990), Scottish actor Jack Lynch (disambiguation), multiple people Jack Ma (born 1964), Chinese entrepreneur and philanthropist Jack Mack (1881–1960), Australian rules footballer Jack Mara (1908–1965), co-owner of the New York Giants football franchise Jack Markell (born 1960), American politician Jack Marsh (c. 1874–1916), Australian first-class cricketer Jack Mayfield (born 1990), American baseball player Jack McBrayer (born 1973), American comedic actor Jack McCall (1852/1853–1877), murderer of Old West legend Wild Bill Hickok Jack McConnell (born 1960), Scottish politician, First Minister of Scotland 2001–2007 Jack McCracken (1912–1958), American basketball player in the 1930s and 1940s Jack McFetridge (1869-1917), Major League Baseball pitcher Jack McKinney (basketball) (1935–2018), American basketball coach Jack McKinney (writer), pseudonym used by American authors James Luceno and Brian Daley Jack McVite (1932–1967), British criminal Jack Moore, multiple people Jack Morelli (born 1962), American comic book letterer Jack Morris (born 1955), American former Major League Baseball pitcher Jack Nance (1943–1996), American actor Jack Narz (1922–2008), American television announcer and game show host Jack Nasher (born 1979), German business psychologist, author, and professor Jack Neo (born 1960), Singaporean film and television actor, host, and director Jack Newman (disambiguation), multiple people Jack Nicholson (born 1937), American actor Jack Nicklaus (born 1940), American golfer Jack Nitzsche (1937–2000), American musician, arranger, producer, songwriter, and film score composer Jack Novak (born 1953), American former professional football player Jack Null (1924–2003), American college basketball coach Jack Oakie (1903–1978), American actor Jack O'Connell (disambiguation), multiple people Jack Ohman (born 1960), American editorial cartoonist Jack Okey (1889–1963), American art director Jack Oleck (1914–1981), American novelist and comic book writer Jack Olsen (1925–2002), American journalist and author Jack O'Neill (disambiguation), multiple people Jack Osbourne (born 1985), English media personality Jack O'Shea (born 1957), Irish former Gaelic footballer Jack Owen (disambiguation), multiple people Jack Paar (1918–2004), American author, comedian, and talk show host