2018 FINA World Swimming Championships (25 m) – Men's 50 metre butterfly

The Men's 50 metre butterfly competition of the 2018 FINA World Swimming Championships (25 m) was held on 14 and 15 December 2018 at the Hangzhou Olympic Sports Center.

Records
Prior to the competition, the existing world and championship records were as follows.

The following new records were set during this competition:

Heats
The heats were started at 9:52.

Swim-off
The swim-off was held on 14 December at 11:07.

Semifinals
The semifinals were held at 19:33.

Final
The final was held at 19:41.