UFC 158: St-Pierre vs. Diaz was a mixed martial arts event held by the Ultimate Fighting Championship on March 16, 2013, at the Bell Centre in Montreal, Quebec, Canada.

Bell Centre formerly known as Molson Centre, is a multi-purpose arena located in Montreal, Quebec, Canada. Opened on March 16, 1996, it is the home arena of the Montreal Canadiens of the National Hockey League (NHL), replacing the Montreal Forum. It is owned by the Molson family via the team's ownership group Groupe CH, and managed via Groupe CH subsidiary Evenko.