XY

XY, or xy, or any of its variants may refer to:

Entertainment

 * Pokémon X and Y, a pair of 2013 role-playing video games in the Pokémon series
 * XY (magazine), a gay male youth magazine that also operated a personals website
 * X, Y, a 1993 novel by Michael Blumlein
 * X&Y, a 2005 album by Coldplay
 * Xy, a member of the band Samael

Film and television

 * Aktenzeichen XY… ungelöst, a German television series first broadcast in 1967
 * Kyle XY, an American sci-fi television series first broadcast in 2006
 * Pokemon The Series: XY, the 17th season of Pokémon and the first and titular season of Pokémon the Series: XY, first broadcast in 2013; named after the games
 * X+Y, a 2014 British film
 * X/Y, a 2014 American film
 * X&Y (film), a 2018 Swedish film
 * "XY", an episode of the 8th season of the television series Castle, first broadcast in 2018
 * XY Chelsea, a 2019 American-British documentary film about Chelsea Manning

Science and technology

 * the XY model, a lattice model of statistical mechanics
 * the XY problem, a problem of communication in software engineering and technical support situations

Genetics

 * XY sex chromosomes, in the XY sex-determination system found in many animals
 * a male, an organism typically having one X and one Y chromosome and producing sperm gametes that fuse with a female gamete during sexual reproduction
 * XY gonadal dysgenesis, also known as Swyer syndrome, a type of hypogonadism resulting in a phenotypical female with functionless gonads

Mathematics

 * $x$ and $y$, symbols commonly used to denote variables in mathematical formulas
 * $(x, y)$-coordinates, a system used to locate a point in two dimensions according to the cartesian coordinate system
 * $X$ and $Y$, symbols conventionally used to denote the domain and codomain of a function
 * The definition of an $f(x, y)$ function that produces a hyperbolic paraboloid

Other uses

 * XY, IATA code of Flynas (formerly Nas Air), a Saudi low-cost airline
 * Xy (digraph), a digraph of the Romanized Popular Alphabet, used to write Hmong
 * XY, aircraft registration prefix for Myanmar