Fastest swim long course 100 metres butterfly (male)
- Who
- Caeleb Dressel
- What
- 49.45 minute(s):second(s)
- Where
- Japan (Tokyo)
- When
- 31 July 2020
The fastest long course 100 m butterfly by a male swimmer is 49.45 seconds, by Caeleb Dressel (USA), at the 2020 Tokyo Olympic games, Tokyo, Japan, on 31 July 2021.
Dressel shaved 0.05 of a second of his own world record in a dominant performance, claiming his third of five gold medals Dressel achieved at the 2020 Tokyo Olympics.