XX or xx may refer to:

  • 20 (number), Roman numeral XX

Film and TV

  • XX (film), a 2017 anthology horror film
  • "XX", an episode of CSI: Crime Scene Investigation (season 4)
  • XX, the production code for the 1969 Doctor Who serial The Seeds of Death
  • XX (web series), a 2020 South Korean web series
  • XX (organization), a fictional organisation in the comic and game XIII

Genetics

  • XX sex chromosomes, in the XY sex-determination system
  • XX male syndrome, also known as de la Chapelle syndrome, a rare congenital intersex condition resulting in a phenotypical male with two X chromosomes
  • XX gonadal dysgenesis, a type of female hypogonadism resulting in non-functioning ovaries
  • XX sex chromosomes, in the XO sex-determination system
  • a female, an organism producing ova gametes that fuse with the male gamete during sexual reproduction, typically having two X chromosomes in the XY and X0 sex determination systems

Music

  • The xx, an English indie rock band
  • X_______X (band), an American no wave band

Albums

  • Toto XX, a 1998 album by Toto
  • XX (Mushroomhead album), 2001
  • xx (The xx album), 2009
  • XX (Great Big Sea album), 2012
  • XX – Two Decades of Love Metal, a 2012 compilation album by HIM
  • XX (O.A.R. album), 2016
  • XX (Mino album), 2018
  • XX, a 2018 album by Note-oriety
  • + + (EP), a 2018 EP, repackaged as [X X] in 2019, by Loona
  • XX, a 2026 album by Fally Ipupa

Songs

  • "xx", a song by Hayley Kiyoko from Expectations
  • "XX", a song by Feid from Ferxxo (Vol 1: M.O.R)

Organisations

  • XX Bomber Command, an inactive United States Air Force unit
  • XX Corps (disambiguation)
  • Legio XX Valeria Victrix or Legion XX, a legion of the Roman Empire

Other uses

  • XX (novel), a 2020 novel by Rian Hughes
  • XX System or Double-Cross System, a British deception operation in the Second World War
  • Les XX, a group of twenty Belgian painters
  • Dos Equis or XX, a brand of Mexican beer
  • <code>xx</code>, to express exponentiation in the initial version of the FORTRAN programming language
  • <code>.xx</code> ("dot XX") is sometimes used in documentation as a placeholder for an arbitrary Country code top-level domain in the Internet domain naming system, as it does not correspond to any real ccTLD or ISO 3166-1 alpha-2 country code.

See also

  • 20 (disambiguation)
  • Double Cross (disambiguation)
  • X (disambiguation)
  • XXX (disambiguation)
  • XXXX (disambiguation)