| Robyn Thorn | |
| Fullname: | Robyn Jean Thorn |
| National Team: | Australia |
| Strokes: | Freestyle |
| Birth Date: | 26 November 1945 |
| Birth Place: | Queensland, Australia |
| Show-Medals: | yes |
Robyn Jean Thorn (born 26 November 1945), also known by her married name Robyn Nock, is an Australian former freestyle swimmer who won the silver medal in the 4×100-metre freestyle relay at the 1964 Summer Olympics in Tokyo.
Coming from Kingaroy, Queensland, Thorn spent the majority of her career in the shadow of fellow Australian Dawn Fraser. Making her debut in the 1962 Commonwealth Games in Perth, Western Australia, Thorn was part of the winning 4×110-yard freestyle relay team, and won silver in the corresponding individual event behind Fraser. Two years later in Tokyo, Thorn was a semifinalist in the 100-metre freestyle, won by Fraser. She combined with Fraser, Lyn Bell and Janice Murphy to finish second, 3.1 seconds behind the United States.