The 2012–13 Big 12 men's basketball season began with practices in October 2012, followed by the start of the regular-season in November.
Conference play began in early January 2013 and concluded in March with the 2013 Big 12 men's basketball tournament at the Sprint Center in Kansas City.
This was the first season in the Big 12 for two former Mountain West and Big East teams, as the TCU Horned Frogs and the West Virginia Mountaineers, respectively, played their first seasons in the conference.
() first place votes Pre-Season All-Big 12 Teams This table summarizes the head-to-head results between teams in conference play.
Several players from the conference declared early for the NBA draft.