Unknown

• a lack of knowledge
• a variable to be solved for in a mathematical equation
• an actor or footballer or singer who is not yet famous
• John Doe, an unknown person
• Unknown unknown, an unanticipated uncertainty in a formal decision model
• Unknown (film), a 2006 movie
• Unknown (magazine), a fantasy magazine published from 1939-1943
• Unknown (Tekken), the final boss and last time-released character of Tekken Tag Tournament
• The Unknown MC, a member in DJ Pied Piper and the Masters of Ceremonies
• The Unknown Comic, the stage name for Canadian-American actor and stand-up comic Murray Langston who usually appeared with a paper bag over his head

See also

• Unknown date, e.g. unknown date of a birth or death
• Unknown bug
• Unown, a Pokémon species
• Unknown soldier (disambiguation)