- Brazilian Grand Prix
- Reutemann heads another Williams 1-2
March 29, 1981: The second race of the season produced another Williams 1-2, although the order was reversed with Carlos Reutemann taking the win from team-mate and defending champion Alan Jones.
- US Grand Prix
- Jones wins as Patrese stars at Long Beach
March 15, 1981: The season started with victory for defending world champion Alan Jones at Long Beach, suggesting it was going to be another long campaign for Williams' rivals. Despite rule changes which removed skirts from cars, it was as-you-were in the USA.