Mortal Kombat X is a fighting video game developed by NetherRealm Studios and published by Warner Bros. Interactive Entertainment. Running on the Unreal Engine 3, it is the tenth main installment in the Mortal Kombat video game series and a sequel to the 2011 game Mortal Kombat. It was released on April 14, 2015 for Microsoft Windows, PlayStation 4, and Xbox One. NetherRealm studio's mobile team developed a version for iOS and Android devices. A version for Xbox 360 and PlayStation 3 was in development but was eventually cancelled because NetherRealm could not get the seventh generation of consoles versions to the quality expected of a Mortal Kombat game. High Voltage Studios developed the PC version of the game, with Polish studio QLoc taking over the work on it shortly after the release of Kombat Pack 1.

Like previous Mortal Kombat games, Mortal Kombat X's gameplay consists of two players, or one player and the CPU, fighting against each other with their selected character, using a large, varied array of character specific attacks. The game contains several modes, such as a story mode, which takes place twenty years after the previous Mortal Kombat game, several 'Tower' modes, which feature dynamically changing challenges, numerous online modes, and the 'Krypt', a mode played in a first-person perspective where players explore the areas unlocking a variety of in-game items.

The console versions of Mortal Kombat X received mostly positive reviews from critics upon release. Most praise was directed at the game's controls, overall gameplay, graphics, story, and characters, with some reviewers calling it the best game in the Mortal Kombat series. However, the PC version of the game was met with mixed reception, with reviewers blaming numerous technical issues (including frequent crashes and slow netcode) for severely hindering the experience. Some critics also particularly disliked the tutorials, microtransactions, and downloadable content. Selling more than 5 million copies, the game was the fastest-selling game in the franchise and the ninth best-selling game in 2015.

An upgraded version of Mortal Kombat X, titled Mortal Kombat XL, was released on March 1, 2016 for PlayStation 4 and Xbox One. This upgrade to the game includes all downloadable content characters from the two released Kombat Packs, almost all bonus alternate costumes available at the time of release, improved gameplay, and improved netcode. This edition was also released for PC on October 4, 2016.