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.
Preseason
() first place votes
Pre-Season All-Big 12 Teams
Player of the Year: Pierre Jackson, Baylor
Newcomer of the Year: Amath M'Baye, Oklahoma
Freshman of the Year: Marcus Smart, Oklahoma State
Rankings
Conference Schedules
Conference matrix
This table summarizes the head-to-head results between teams in conference play. (x) indicates games remaining this season.
Baylor
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!colspan=12 style="background:#003015; color:#FECB00;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#003015"|2013 Big 12 tournament
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| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Iowa State
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!colspan=12 style=""| Big 12 Regular Season
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!colspan=12 style=""| 2013 Big 12 Tournament
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|-
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| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Kansas
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!colspan=12 style="background:#0049AF; color:#F20030;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#0049AF"|2013 Big 12 tournament
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| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Kansas State
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!colspan=12 style="background:#512888; color:#FFFFFF;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#512888"|2013 Big 12 tournament
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| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Oklahoma
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!colspan=12 style="background:#960018; color:#FFFDD0;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#960018"|2013 Big 12 tournament
|-
| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Oklahoma State
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!colspan=12 style="background:#000000; color:#FF6600;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#000000"|2013 Big 12 tournament
|-
| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
TCU
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!colspan=12 style="background:#520063; color:#FFFFFF;"| Big 12 Regular season
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!colspan=12 style="text-align: center; background:#520063"|2013 Big 12 tournament
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| colspan="12" | *Non-conference game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Texas
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!colspan=12 style="background:#CC5500; color:#FFFFFF;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#CC5500"|2013 Big 12 tournament
|-
| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Texas Tech
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!colspan=12 style="background:#CC0000; color:#000000;"| Big 12 Regular Season
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!colspan=12 style="text-align: center; background:#CC0000"|2013 Big 12 tournament
|-
| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
West Virginia
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!colspan=12 style="background:#003366; color:#FFCC00;"| Big 12 Regular Season
|-
!colspan=12 style="text-align: center; background:#003366"|2013 Big 12 tournament
|-
| colspan="12" | *Non-Conference Game. Rankings from AP poll. All times are in Central Time. (#) Number seeded with region. |}
Postseason
Big 12 tournament
March 13–16, 2013– Big 12 Conference Basketball Tournament, Sprint Center, Kansas City, MO.