| Event: | Men's 400 metre freestyle S8 |
| Games: | 2016 Summer |
| Venue: | Olympic Aquatics Stadium |
| Dates: | 8 September 2016 |
| Competitors: | 12 |
| Nations: | 8 |
| Gold: | Oliver Hynd |
| Goldnpc: | GBR |
| Silver: | Xu Haijiao |
| Silvernpc: | CHN |
| Bronze: | Wang Yinan |
| Bronzenpc: | CHN |
| Prev: | 2012 |
| Next: | 2020 |
The men's 400 metre freestyle S8 event at the 2016 Paralympic Games took place on 8 September, at the Olympic Aquatics Stadium.
Two heats were held, both with six swimmers. The swimmers with the eight fastest times advanced to the final.
, the existing World and Paralympic records were as follows.
| World record | 4:23.76 | Sheffield, Great Britain | 30 July 2016 | ||
| Paralympic record | 4:26.25 | Beijing, China | 9 September 2008 | ||
| 2016 World leading | 4:23.76 | Sheffield, Great Britain | 30 July 2016 |
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 4 | 4:41.10 | Q | |||
| 2 | 3 | 4:41.18 | Q | |||
| 3 | 5 | 4:41.93 | Q | |||
| 4 | 6 | 4:51.81 | ||||
| 5 | 2 | 4:54.24 | ||||
| 6 | 7 | 4:56.85 |
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 4 | 4:31.90 | Q | |||
| 2 | 3 | 4:38.46 | Q | |||
| 3 | 5 | 4:40.64 | Q | |||
| 4 | 6 | 4:41.06 | Q | |||
| 5 | 2 | 4:43.87 | Q | |||
| 6 | 7 | 4:56.29 |
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 4 | 4:21.89 | WR | ||||
| 7 | 4:25.65 | |||||
| 2 | 4:32.78 | |||||
| 4 | 3 | 4:33.97 | ||||
| 5 | 5 | 4:36.26 | ||||
| 6 | 1 | 4:39.04 | ||||
| 7 | 6 | 4:39.79 | ||||
| 8 | 8 | 4:48.23 |