2003 Big 12 Conference baseball tournament
The 2003 Big 12 Conference baseball tournament was once again held at AT&T Bricktown Ballpark in Oklahoma City, OK from May 21 through 25. Texas won their second consecutive tournament and earned the Big 12 Conference's automatic bid to the 2003 NCAA Division I baseball tournament. The tournament mirrored the format of the College World Series, with two 4-team double-elimination brackets and a final championship game.
Regular Season Standings
Source:| Place | Seed | Team | Conference | Conference | Conference | Conference | Overall | Overall | Overall |
| Place | Seed | Team | W | L | % | GB | W | L | % |
| 1 | 1 | 20 | 7 | – | 47 | 18 | |||
| 2 | 2 | 19 | 8 | 1 | 45 | 19 | |||
| 2 | 3 | Texas | 19 | 8 | 1 | 50 | 20 | ||
| 4 | 4 | Missouri | 15 | 11 | 4.5 | 36 | 22 | ||
| 5 | 5 | 15 | 12 | 5 | 45 | 23 | |||
| 6 | 6 | 14 | 13 | 6 | 34 | 24 | |||
| 7 | 7 | 10 | 17 | 10 | 23 | 31 | |||
| 8 | 8 | 9 | 18 | 11 | 35 | 28 | |||
| 9 | – | 8 | 18 | 11.5 | 30 | 25 | |||
| 10 | – | 5 | 22 | 15 | 15 | 37 |
- Colorado and Iowa State did not sponsor baseball teams.
Tournament
- Kansas State and Texas Tech did not make the tournament.