The Men's 100 metre butterfly competition of the 2018 African Swimming Championships was held on 11 September 2018.

Records Prior to the competition, the existing world and championship records were as follows. Name Nation Time Location DateWorld recordMichael Phelps49.82Rome1 August 2009African recordChad le Clos50.56Kazan8 August 2015Championship recordJason Dunford52.49Johannesburg7 December 2008

Results Heats The heats were started on 11 September at 09:30.

Rank Name Nationality Time Notes 1 Alaric Basson54.69 Q 2 Mohamed Samy55.20 Q 3 Abeiku Jackson55.57 Q 4 Yusuf Tibazi55.64 Q 5 Ralph Goveia55.94 Q 6 Abdelrahman Sameh56.00 Q 7 Mohamed Malek Masmoudi56.70 Q 8 Bradley Vincent57.30 Q 9 Samy Boutouil57.77 10 Daniel Francisco58.82 11 Kobe Ndebele59.22 12 Chase Onorati59.59 13 Herinirina John Rakotomavo 14 Isihaka Irankunda 15 Adam Moncherry 16 Ganira Belly-Cresus 17 Troy Nestor Pina 18 Ovesh Purahoo 19 Edilson Paco 20 Simonga Dlamini 21 Sithembiso Mamba 22 Billy-Scott Irakose 23 Ayaan Chand Onyemeehi OputeIsobo Confidence

Final The final was started on 12 September.

Rank Lane Name Nationality Time Notes 5 Mohamed Samy 53.72 6 Yusuf Tibazi 54.20 2 Ralph Goveia 54.53 4 4 Alaric Basson 54.79 5 3 Abeiku Jackson 55.18 6 7 Abdelrahman Sameh 56.53 7 1 Mohamed Malek Masmoudi 56.59 8 8 Bradley Vincent 56.66

References