*Affiliate members only compete in Woman's Rowing.
The Big 12 Conference sponsors championships in 23 sports, 10 men's and 13 women's. The first conference championship awarded was the 1996 softball post season tournament championship, which was won by Oklahoma.
Starting in 2011 the football champion will be decided by regular season play. Previously divisional titles were awarded based on regular-season conference results, with the teams with the best conference records from the North and South playing in the Big 12 Championship Game for the Big 12 title. Baseball, basketball, soccer, and tennis titles are awarded in both regular-season and tournament play. Cross country, golf, gymnastics, rowing, swimming and diving, track and field, and wrestling titles are awarded during an annual meet of participating teams. The volleyball and softball titles are awarded based on regular-season play. Softball previously held a post season tournament.
All current Big 12 members sponsor baseball except Iowa State, which dropped the sport after the 2001 season. All former Big 12 members sponsored the sport throughout their tenures in the conference except Colorado, which never sponsored baseball during its time in the Big 12.
An X denotes never competing in a year that awarded the post season championship. The Big 12 counts shared division championships as a full championship for each school, regardless of what school went on to play in the Big 12 title game.
Note: While the team playing in the championship game is popularly regarded as the divisional champion, the Big 12 did officially recognize co-champions in football, just like it does in other sports. As a result, the following teams are also recognized as champions by the Big 12: North Co-Champions: Kansas State (1999), Nebraska (2000, 2001, 2008), Iowa State (2004), Kansas (2007), Missouri (2010) South Co-Champions: Texas (2002, 2008), Texas Tech (2008), Oklahoma State (2010), Texas A&M (2010) 
2011 – present
When Nebraska and Colorado left the conference after the 2010 season, it left the conference with only 10 members. The conference did not replace the two teams and therefore eliminated the Big 12 Championship game. Under the new format, every team plays each other and the team with the best conference record wins the Big 12 title. In the event of a tie between two teams or more teams for the best conference record, then they were determined co-champions. Through the 2013 season, the winner of the head-to-head game earned the BCS berth in the Fiesta Bowl. This has since been changed and the league will recognize a tie-breaker starting in 2015. The change was made after the B12 was left out of the inaugural four-team College Football Invitational in 2014. The B12 presented TCU and Baylor as co-champs to the College Football Committee in 2014, despite Baylor having the head to head win over TCU. The move was seen as a play by the conference to get two teams invited into the new format, which backfired, leaving both teams out.
With the launch of the College Football Playoff (CFP) in 2014, which coincided with a reworking of bowl tie-ins, the Big 12 tie to the Fiesta Bowl ended.
The Big 12's primary bowl partner is now the Sugar Bowl, In years when that game is not a CFP semifinal, the top teams from the Big 12 and SEC, as chosen by the CFP selection committee, will play one another. If either conference provides a team for the CFP semifinals, the top non-playoff team from that conference will go to the Sugar Bowl.
When the Sugar Bowl is hosting a semifinal, the top Big 12 team not involved in the playoff will receive a berth in either the Cotton Bowl, Fiesta Bowl, or Peach Bowl.
As of the 2014–15 school year, rowing is the only Big 12 sport with affiliate members. Before that school year, the Big 12 and Conference USA (C-USA) had a rowing alliance in which all Big 12 rowing schools would participate in the C-USA championship as well as the Big 12 championship. C-USA dropped rowing after the departure of most of its rowing members for other conferences. The Big 12 then took in the three remaining schools from the C-USA rowing league (Alabama, Old Dominion, and Tennessee) as single-sport affiliates.