X2 may refer to:
Mathematics edit:
Square (algebra), also known as the "algebraic square", a concept in algebra,
Chi-squared distribution, a theoretical probability distribution widely used in inferential statistics,
Films edit:
X2 (film), a 2003 American sequel to the 2000 film X-Men. Also known as X-Men United.,
xXX: State of the Union, also known as X2 or XXX², a 2005 American film,
Video games edit:
X2 (video game), a 1997 video game,
Final Fantasy X-2, a 2003 role-playing video game,
Mega Man X2, a 1994 platform game,
X2: The Threat, a 2003 space simulation game,
Dance Dance Revolution X2, a 2010 upcoming music video game for the PlayStation 2 by Konami,
X2, the main character in Star Wars Battlefront: Elite Squadron,
Transport edit:
Bell X-2, an experimental supersonic aircraft,
Sikorsky X2, a prototype, coaxial high-speed helicopter,
SpaceShipOne flight 17P, also known as "X2", the second Ansari X Prize flight,
Skycycle X-2, a rocket used by Evel Knievel,
HMS X2, a Royal Navy submarine,
Bathyscaphe Trieste II, also known as X-2, the US Navy bathyscaphe based on the Trieste,
SJ X2, used for the X2000 train system in Sweden,
Kawasaki X2, a personal water craft,
X-2 Dragonfly, the company designation of the Rotor-Craft XR-11 experimental helicopter of the late 1940s,
X-2 Rocket, the spacecraft used in Mission: Space in Epcot,
X2 (New York City bus),
Computer edit:
X2 (protocol), a pre-V.90 standard for 56k downstream modem communications,
Athlon 64 X2, the first dual-core desktop CPU manufactured by AMD,
A two-lane PCI Express slot,
A type of 10-gigabit Ethernet optical transceiver,
Sony Ericsson Xperia X2 smartphone,
Other edit:
X2 (roller coaster), a Roller Coaster at Six Flags Magic Mountain,
Sendo X2, a Series 60 mobile phone,
The counterintelligence branch of the Office of Strategic Services, an American agency during World War II,
X-2, a hydrofoil owned by the Venture family on The Venture Bros.,
a keyboard synthesizer sold by Korg in the 1990s,
X2 is a transport interface used to connect enodeBs together in a LTE/4G network,
X2 is also a fictional character created by renowned Pakistani writer Ibn-e-Safi in Imran Series