| Year: | 2011 |
| Conference: | Atlantic Sun |
| Division: | I |
| Gender: | Men's |
| Teams: | 8 |
| Arena: | University Center |
| City: | Macon, Georgia |
| Champions: | Belmont Bruins |
| Titlecount: | 4th |
| Coach: | Rick Byrd |
| Coachcount: | 4th |
The 2011 Atlantic Sun men's basketball tournament was the 33rd edition of the Atlantic Sun Conference (A-Sun)'s Men's Basketball Tournament. It took place from March 2–5, 2011 at the University Center on the campus of Mercer University in Macon, Georgia. The Belmont University Bruins won the tournament, defeating the University of North Florida Ospreys 87-46 in the final.
The top eight eligible men's basketball teams in the Atlantic Sun Conference received a berth in the conference tournament. After the 20-game conference season, teams are seeded by conference record. Florida Gulf Coast University and the University of South Carolina Upstate were not eligible to compete due to NCAA reclassification.
Asterisk denotes game ended in overtime.