The 1951 Australian Grand Prix was a Formula Libre motor race held at a street circuit in Narrogin, Western Australia on 5 March 1951.

The first car over the line was the MG TC special of South Australian Steve Tillett.

The Australian Grand Prix title was however to be awarded to the driver setting the fastest outright time, regardless of handicap.

Pratley won the race by 96 seconds over the Delahaye of Dick Bland.

Both Tillett and Pratley were awarded Commonwealth Jubilee Trophies for their victories in what was effectively two races in one.