The Men's 100 metre freestyle swimming events for the 2020 Summer Paralympics took place at the Tokyo Aquatics Centre from August 25 to September 1, 2021.
The S4 category is for swimmers who have function in their hands and arms but can't use their trunk or legs to swim.
The final in this classification took place on 26 August 2021: The S6 category is for swimmers who have short stature, arm amputations, or some form of coordination problem on one side of their body.
The final in this classification took place on 1 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 25 August 2021: The S10 category is for swimmers who have minor physical impairments, for example, loss of one hand.