Martín Gastón Demichelis (born 20 December 1980) is an Argentine professional footballer who plays for Manchester City in England, mainly as a central defender, although he can operate occasionally as a defensive midfielder.

Demichelis lost his place in the national side in November 2011, after a World Cup qualifier against Bolivia. A two and a half year absence followed, until he gained an unexpected inclusion in Alejandro Sabella's provisional 30-man squad for the 2014 World Cup. He made his return to the national side in a 3–0 win against Trinidad and Tobago.