JOSS (an acronym for JOHNNIAC Open Shop System) was one of the very first interactive, time-sharing programming languages. JOSS I, developed by J. Clifford Shaw at RAND was first implemented, in beta form, on the JOHNNIAC computer in May 1963. The full implementation was deployed in January 1964, supporting five terminals and the final version, supporting ten terminals, was deployed in January 1965.

Joss may refer to:

• Joss Ackland (born 1928), British actor
• Joss Ambler (1900–1959), Australian-born British film and television actor
• Joss Christensen (born 1991), American freestyle skier and 2014 Olympic gold medalist
• Joss Fritz (c. 1470-c. 1525), insurgent in Germany
• Joss Labadie (born 1990), English footballer
• Joss McKinley (born 1981) English photographic artist
• Joss Naylor, (born 1936), English fell runner
• Joss Whedon (born 1964), American screenwriter, film and television director and producer, television series creator, comic book author and composer
• George (Duala king) or Joss, a late 18th century king of the Duala people of Cameroon