The women's 400 metres T11 event at the 2020 Summer Paralympics in Tokyo took place between 27 and 28 August 2021.

The T11 category is for athletes with a visual impairment.

A T11 athlete may be entirely without sight, or be able to perceive light, but have no ability to see the shape of a hand at any distance.

T11 athletes commonly run with guides.

Prior to the competition, the existing records were as follows:[1] Heat 1 took place on 27 August 2021, at 11:01:[2] Heat 2 took place on 27 August 2021, at 11:09:[3] Heat 3 took place on 27 August 2021, at 11:17:[4] Heat 4 took place on 27 August 2021, at 11:25:[5] Semi-final 1 took place on 27 August 2021, at 19:40:[6] Semi-final 2 took place on 27 August 2021, at 19:48:[7] The final took place on 28 August 2021, at 11:45:[8]