Lex is a given name. It is a common male name in the Netherlands, and is sometimes short for Alexander, Alexandra or Lexington.
People bearing the name include:
Lex Banning (1921-1965), Australian lyric poet
Lex Barker (1919-1973), American actor
Lex Davison (1923-1965), Australian racing driver
Lex van Delden (1919-1988), Dutch composer
Lex Frieden, disability activist and professor
Lex Gigeroff (c. 1962-2011), Canadian television writer and actor best known as co-creator of the science fiction series Lexx
Lex Goudsmit (1913-1999), Dutch actor
Robert A. Green (1892-1973), U.S. Representative from Florida
Lex Humphries (1936-1994), jazz drummer
Lex Lang (born 1965), American voice actor
Lex Lasry (born 1948), Australian lawyer and a judge on the Supreme Court of Victoria
Lex Law, Scottish former footballer
Lex Luger (born 1958), ring name of long-time professional wrestler Lawrence Wendell "Larry" Pfohl
Lex McLean (1908-1975), Scottish comedian
Lex Schoenmaker (born 1947), Dutch former football player and manager
Alexander Lex Shrapnel (born 1979), English actor
Lex Staley, half of the syndicated morning team Lex and Terry
Lex van den Berghe, a contestant in the television show Survivor: Africa
Fictional characters so named include:
Lex Luthor, nemesis of Superman
Alexander Lexington, a Marvel Comics mutant
Alexis "Lex" Murphy, in the Jurassic Park novel and film franchise
Lex, in the TV series The Tribe (1999-2003) played by Caleb Ross
Lex, in the game Fire Emblem: Genealogy of the Holy War (1996)
Lexx a sentient spaceship in the tv series of the same name.