2021 FINA World Swimming Championships (25 m) – Men's 100 metre backstroke

The Men's 100 metre backstroke competition of the 2021 FINA World Swimming Championships (25 m) was held on 16 and 17 December 2021.

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

Heats
The heats were started on 16 December at 10:56.

Swim-off
The swim-off was held on 16 December at 12:42.

Semifinals
The semifinals were started on 16 December at 18:16.

Final
The final was held on 17 December at 18:07.