The Women's 100 metre butterfly swimming events for the 2020 Summer Paralympics took place at the Tokyo Aquatics Centre from 25 August to 3 September 2021.
The S8 category is for swimmers who have a single amputation, or restrictive movement in their hip, knee and ankle joints.
The final in this classification took place on 3 September 2021: The S9 category is for swimmers who have joint restrictions in one leg, or double below-the-knee amputations.
The final in this classification took place on 2 September 2021: The S10 category is for swimmers who have minor physical impairments, for example, loss of one hand.
The final in this classification took place on 25 August 2021: The S14 category is for swimmers who have an intellectual impairment.