Leamy, 30, won 57 caps for Ireland and was part of the 2009 Six Nations grand slam winning squad.
"I find it hard to put into words how much it has meant to me to play for Munster and Ireland," Leamy told Munster's website.
"It was a dream come true and I was very lucky to play with some of the greatest players ever to wear the jerseys and feel blessed that I was part of winning teams.
"I've had a great career, wish it had gone on a little longer but I'd like to thank all the coaches, players, medical staff and management who have helped me over the past decade."
Leamy, who played in two World Cups, featured in just seven games for Munster this season.