| 1966 FIM Motocross World Championship | |
|---|---|
| Organizer | FIM |
| Duration | 27 March/2 October |
| Number of races | 29 |
| Number of manufacturers | 9 |
| Champions | |
| 500cc |  Paul Friedrichs |
| 250cc |  Torsten Hallman |
The 1966 Motocross World Championship was the 10th edition of the Motocross World Championship organized by the FIM and reserved for 500cc and 250cc motorcycles.