| Year: | 2003 |
| Division: | III |
| Teams: | 48 |
| Finalfourcity: | Salem, Virginia |
| Champions: | Williams |
| Titlecount: | 1st |
| Runnerup: | Gustavus Adolphus |
| Gamecount: | 1st |
| Semifinal1: | Wooster |
| Finalfourcount: | 1st |
| Semifinal2: | Hampden-Sydney |
| Finalfourcount2: | 2nd |
| Coach: | Dave Paulsen (Williams) |
| Mop: | Benjamin Coffin (Williams) |
| Attendance: | 50870 |
The 2003 NCAA Division III men's basketball tournament was the 29th annual single-elimination tournament to determine the national champions of National Collegiate Athletic Association (NCAA) men's Division III collegiate basketball in the United States.
The field contained forty-eight teams, and each program was allocated to one of four sectionals. All sectional games were played on campus sites, while the national semifinals, third-place final, and championship finals were contested at the Salem Civic Center in Salem, Virginia.[1]
Williams defeated Gustavus Adolphus, 67–65, in the championship, clinching their first national title.
The Ephs (31–1) were coached by Dave Paulsen. Paulsen would later coach at Division I programs Bucknell and George Mason.
Benjamin Coffin, also from Williams, was named Most Outstanding Player.