The women's 400 metres T20 event at the 2024 Summer Paralympics in Paris, is scheduled to take place on 3-4 September 2024.

The event is open to T20 athletes.

These athletes have an intellectual impairment.

[1] Prior to the competition, the existing records were as follows:[2] The Heats were held on 2 September.

First 3 in each heat (Q) and the next 2 fastest (q) advance to the final The final took place on 3 September.