The following is an overview of the events of 1921 in motorsport including the major racing events, motorsport venues that were opened and closed during a year, championships and non-championship events that were established and disestablished in a year, and births and deaths of racing drivers and other motorsport people.
Annual events
The calendar includes only annual major non-championship events or annual events that had own significance separate from the championship. For the dates of the championship events see related season articles.