Swimming at the 2008 Summer Paralympics – Men's 100 metre butterfly S13

The men's 100 metre butterfly S13 event at the 2008 Paralympic Games took place on September 7, at the Beijing National Aquatics Center.

Three heats were held, with five swimmers in the first heat and six swimmers in each of the second and third heat. The swimmers with the eight fastest times advanced to the final; there, they all competed in a single final heat to earn final placements.