X-Men vs. Street Fighter (Japanese: エックスメン VS. ストリートファイター Hepburn: Ekkusu Men bāsasu Sutorīto Faitā) is a crossover fighting video game developed and published by Capcom. It is Capcom's third fighting game to feature Marvel Comics characters, following X-Men: Children of the Atom and Marvel Super Heroes, and the first installment in the Marvel vs. Capcom series. As the title suggests, the game includes characters from Marvel's X-Men franchise and the cast from Capcom's Street Fighter series. Originally released as a coin-operated arcade game in 1996, it was eventually ported to the Sega Saturn in 1997 and the PlayStation in 1998.

X-Men vs. Street Fighter features gameplay similar to Street Fighter, but incorporates dual-character selection and tag team-based combat. Each player selects two characters to compete in a one-on-one battle, attempting to defeat the opposing team. The players are given the ability to switch between their characters at any point during the match. The game also incorporates numerous elements from X-Men: Children of the Atom and Marvel Super Heroes.

The game was released to generally positive reviews, with critics praising its gameplay and sprite animation quality. While the Sega Saturn port received praise for maintaining the experience of the original arcade version, the PlayStation port was met with mixed to negative critical reception for removing several features, such as tag team battles. The changes were done in response to the technical limitations of the PlayStation. A sequel to the game, Marvel Super Heroes vs. Street Fighter, was released in 1997.