Street Fighter II: The World Warrior (Japanese: ストリートファイターⅡ -The World Warrior-^?) is a competitive fighting game originally released for the arcades in 1991. It is the second entry in the Street Fighter series and the arcade sequel to the original Street Fighter released in 1987. It is Capcom's fourteenth title that runs on the CP System arcade hardware. Street Fighter II improves upon the many concepts introduced in the first game, including the use of command-based special moves and a six-button configuration, while offering players a selection of multiple playable characters, each with their own unique fighting style, and introducing a combo system and competitive multiplayer combat between two players.

The success of Street Fighter II is credited for starting the fighting game boom during the 1990s which inspired other game developers to produce their own fighting game franchises, popularizing the genre, and setting off a renaissance for the arcade game industry in the early 1990s. It was then ported to the Super Nintendo Entertainment System home console, for which it became a long-lasting system-seller. Its success led to a sub-series of updated versions (see below), each offering additional features and characters over previous versions, as well as several home versions.