| Birth Date: | 17 September 1898 |
| Birth Place: | Le Mans, France |
| Death Place: | Gien, France |
| Sport: | Cycling |
| Show-Medals: | yes |
Robert "Toto" Grassin (17 September 1898 – 26 June 1980) was a French cyclist who specialized in motor-paced racing. In this discipline he won the national championships in 1924 and the UCI Motor-paced World Championships in 1925.