Swimming at the 2019 Pan American Games – Men's 100 metre butterfly

The men's 100 metre butterfly competition of the swimming events at the 2019 Pan American Games was held on August 7, 2019 at the Villa Deportiva Nacional Videna cluster.

Records
Prior to this competition, the existing world and Pan American Games records were as follows:

Heats
The first round was held on August 7.

Final B
The B final was also held on August 7.

Final A
The A final was also held on August 7.