The 2011 Atlantic Sun men's basketball tournament was the 33rd edition of the Atlantic Sun Conference (A-Sun)'s Men's Basketball Tournament.

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.

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.