The men's 400 metres T47 event at the 2020 Summer Paralympics in Tokyo, took place between 3 and 4 September 2021.

The T47 category is for athletes who have a single below elbow or wrist amputation or similar disability, with normal function in both legs.

Prior to the competition, the existing records were as follows:[1] Heat 1 took place on 3 September 2021, at 10:38:[2] Heat 2 took place on 3 September 2021, at 10:45:[3] The final took place on 4 September 2021, at 21:01:[4]