| Event: | Women's 400 metre freestyle S8 |
| Games: | 2016 Summer |
| Venue: | Olympic Aquatics Stadium |
| Dates: | 8 September |
| Competitors: | 13 |
| Nations: | 8 |
| Goldnpc: | AUS |
| Silver: | Jessica Long |
| Silvernpc: | USA |
| Bronze: | Stephanie Millward |
| Bronzenpc: | GBR |
The women's 400 metre freestyle S8 event at the 2016 Paralympic Games took place on 8 September 2016, at the Olympic Aquatics Stadium. Two heats were held, the first with six swimmers and the second with seven swimmers. The swimmers with the eight fastest times advanced to the final, which was won by Australia's Lakeisha Patterson, in a world record time of 4:40.33.
, the existing World and Paralympic records were as follows.
| World record | 4:40.44 | Toronto, Canada | 20 March 2015 | ||
| Paralympic record | 4:42.28 | London, Great Britain | 31 August 2012 | ||
| 2016 World leading | 4:45.06 | Adelaide, Australia | 9 April 2016 |
10:01 8 September 2016
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 4 | 4:57.37 | Q | |||
| 2 | 5 | 5:09.85 | Q | |||
| 3 | 3 | 5:16.02 | Q | |||
| 4 | 2 | 5:20.20 | Q | |||
| 5 | 7 | 5:26.27 | ||||
| 6 | 6 | 5:36.21 |
10:09 8 September 2016
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 4 | 4:48.26 | Q | |||
| 2 | 5 | 4:59.95 | Q | |||
| 3 | 3 | 5:13.99 | Q | |||
| 4 | 7 | 5:21.09 | Q | |||
| 5 | 2 | 5:24.51 | ||||
| 6 | 6 | 5:25.08 | ||||
| 7 | 1 | 5:41.36 |
17:54 8 September 2016
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 5 | 4:40.33 | WR PR | ||||
| 4 | 4:47.82 | |||||
| 3 | 4:49.49 | |||||
| 4 | 6 | 5:02.13 | ||||
| 5 | 2 | 5:12.01 | ||||
| 6 | 8 | 5:16.25 | ||||
| 7 | 7 | 5:16.38 | ||||
| 8 | 1 | 5:20.31 |