Platform game, or platformer, is a video game genre characterized by jumping to and from suspended platforms or over obstacles. It must be possible to control these jumps and to fall from platforms or miss jumps. The most common unifying element to these games is a jump button; other jump mechanics include swinging from extendable arms, as in Ristar or Bionic Commando, or bouncing from springboards or trampolines, as in Alpha Waves. These mechanics, even in the context of other genres, are commonly called "platforming," a verbification of the term "platform." Games where jumping is automated completely, such as The Legend of Zelda: Ocarina of Time, fall outside of the genre.

Platform games originated in the early 1980s, and 3D successors were popularized in the mid-1990s. The term itself describes games where jumping on platforms is an integral part of the gameplay, and came into use some time after the genre had been established, but no later than 1983. However, it is not a pure genre and is very frequently coupled with elements of other genres, such as the shooter elements in Contra, the adventure elements of Flashback or the RPG elements of Castlevania: Symphony of the Night. As long as the platform mechanic remains a prominent part of the gameplay, it may still correctly be termed a platformer. Because of this, there are many diverse sub-genres of platformers.

The genre has been the result of a great deal of cross-pollination of ideas between platforms and across national borders. While commonly associated with console gaming, there have been many important platform games released to arcades, as well as for handheld systems and home computers. Europe, North America, and Japan have played major parts in the genre's evolution. Platformers are thematically diverse, ranging from cartoony "mascot" games to science fiction and fantasy epics.

Platformers were, at one point, the most popular genre of video game. At the peak of their popularity, it is estimated that between one quarter and one third of console games were platformers. No genre before or since has been able to achieve a similar market share. As of 2006, the genre is far less dominant, representing a 2% market share, but still commercially viable, with a number of games selling in the millions of units.

Single screen era

Space Panic, a 1980 arcade release, is sometimes credited as the first platform game, but the distinction is contentious, since the player had no ability to jump, swing, or bounce, or fall, and as such, does not satisfy most modern definitions of the genre. However, it was clearly an influence on the genre, with gameplay centered on climbing ladders between different floors, a common element in many early platform games.