The 2020 FIM Motocross World Championship was the 64th FIM Motocross World Championship season. It had 18 events, starting at Matterley Basin on 1 March and ending at Pietramurata, Italy on 8 November. No races were held from April to July due to the COVID-19 pandemic.

The FIM Motocross World Championship is the premier championship of motocross racing, organized by the Fédération Internationale de Motocyclisme (FIM), divided into two distinct classes: MXGP and MX2. Race duration is 30 minutes plus two laps per race. The series runs 18 events with two races per class at each round. The FIM Women's Motocross World Championship (MXW) is a women-only motorcross championship, inaugurated in 2005, and is a feeder series to the FIM Motocross World Championship.