Swimming at the 2018 Summer Youth Olympics – Boys' 100 metre butterfly
The boys' 100 metre butterfly event at the 2018 Summer Youth Olympics took place on 8 and 9 October at the Natatorium in Buenos Aires, Argentina. Results

Heats
The heats were started on 8 October at 10:30. Semifinals
The semifinals were started on 8 October at 18:32. Swim-off
The swim-off was held on 9 October at 11:29. Final
The final was held on 9 October at 18:46. References

Swimming at the 2018 Summer Youth Olympics