Swimming at the 2024 Summer Olympics – Men's 100 metre butterfly

The men's 100 metre butterfly event at the 2024 Summer Olympics will be held from Augurst 2 to August 3 2024 at the Paris Aquatics Centre.

Records
Prior to this competition, the existing records were as follows.

Qualification
A National Olympic Committee (NOC) may enter a maximum of two qualified athletes in each individual event, but only if both of them have attained the Olympic Qualifying Time (OQT). One athlete per event can potentially enter if they meet the Olympic Consideration Time (OCT), or if the total quota of 852 athletes has not been targeted. NOCs may also permit swimmers regardless of time (one per gender) under a Universality place since they have no swimmers attaining either of the standard entry times (OQT/OCT).

Following the end of the qualification window, World Aquatics will assess the number of swimmers who have achieved the OQT, the number of relay-only swimmers, and the number of Universality places, before inviting those with OCT to fulfill the total quota of 852. Additionally, OCT places will be distributed by event according to the position of the World Aquatics Rankings during the qualifying deadline.

Time standards
The qualifying time standards must be obtained at the 2023 and 2024 World Championships, continental championships, continental swimming meets, national championships and selection trials, and various international meets approved by World Aquatics in the period between 1 March 2023 and 23 June 2024.

The following table outlines the qualifying time standards for Paris 2024 for this event: * OQTs correspond to the time achieved by a fourteenth-place swimmer in his or her respective preliminary heat of each event at the previous Games.

ª Because the fourteenth-place swimmer achieved a standard slower than the OQT in Tokyo 2020, the OQT used at the previous Games will remain constant.

^ OCTs are derived by adding 0.5% of the OQT standard.

Competition format
The competition consists of three rounds: heats, semifinals, and a final. The swimmers with the best 16 times in the heats advance to the semifinals. The swimmers with the best 8 times in the semifinals advance to the final. Swim-offs are used as necessary to break ties for advancement to the next round.

Schedule
All times are Central European time (UTC+1)

Semifinals
The swimmers with the best 8 times, regardless of heat, advanced to the final.