XX

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 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
 * 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

Music

 * The xx, a British indie band
 * X_______X (band), a Cleveland 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

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
 * , to express exponentiation in the initial version of the FORTRAN programming language