Cecil Mamiit is the defending champion of the Men's Singles competition of the 2011 SEA Games but lost in the semifinals to Christopher Rungkat. Rungkat won the title by beating top seed Danai Udomchoke 6–2, 6–2 in the final.
Medalists Men's Singles Indonesia Christopher Rungkat Thailand Danai Udomchoke Indonesia Elbert Sie Philippines Cecil Mamiit
Draw
Seeds The top seed received bye to the quarterfinals.
Main draw
References Draw SEAG2011 Start/Result Lists - Tennis