| Birth Date: | 25 July 1892 |
| Birth Place: | Långedrag, Sweden |
| Death Date: | 12 October 1943 (aged 51) |
| Death Place: | Bremen, Germany |
| Sport: | Sailing |
| Club: | Royal Gothenburg Yacht Club |
| Show-Medals: | yes |
Otto Torsten Johan Aust (25 July 1892 – 12 October 1943) was a Swedish sailor.[1] He was a crew member of the boat Kerstin that won the bronze medal in the 6 m class at the 1912 Summer Olympics.