The Men's 50 metre butterfly competition at the 2019 World Championships was held on 21 and 22 July 2019.

[1][2] The defending champion Ben Proud finished 7th in the final.

The winner, Caeleb Dressel, set a competition record in the final, winning in 22.35 seconds.

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

The heats were held on 21 July at 11:02.