

Introduction
Hannah Margaret McNair MacNeil (born 26 February 2000) is a Canadian swimmer. She is the current world champion and Americas record holder in the 100 meter butterfly event (55.83).
Career
A native of London, Ontario, MacNeil competed for Sir Frederick Banting Secondary School and the London Aquatic Club prior to her acceptance at the University of Michigan.She placed sixth in the 100 metre butterly event trials for Canada's 2016 Olympic team.
MacNeil was part of the Canadian women's team at the 2019 World Championships in Gwangju.She first won a bronze medal as part of the 4×100 m freestyle relay team, alongside Penny Oleksiak, Taylor Ruck, Kayla Sanchez, and Rebecca Smith. MacNeil next competed in and won gold in the women's 100 metre butterfly, beating four-time World and reigning Olympic champion Sarah Sjöström, in what was considered a major upset.