The Phillip Island Grand Prix Circuit is a motor racing circuit on Phillip Island, Victoria, Australia. The current layout was first used in 1956.
Motor racing on Phillip Island began in 1928 with the running of the 100 Miles Road Race, an event which has since become known as the first Australian Grand Prix. It utilised a high speed rectangle of local closed-off public roads with four similar right hand corners. The course length varied, with the car course approximately 6 miles (9.7 km) per lap, compared to the motorcycle circuit which was approximately 10 miles (16 km) in length. The circuit was the venue for the Australian Grand Prix through to 1935 and it was used for the last time on 6 May 1935 for the Jubilee Day Races.
Other significant events staged at the Phillip Island road circuit included the Victorian Centenary Grand Prix of 1934 and the 1936 Australian Tourist Trophy. A triangular circuit utilising one leg of the original rectangular course was subsequently mapped out and used for racing from 1936 to 1940.
In 1951, a group of six local businessmen decided to build a new track. About 2 km away from the original circuit, it still bears the corner name signs of the original circuit. As the piece of available land was on the edge of the coast, the track is known for its steep grades – the highest 57 metres – which caused cost overruns and delays in track opening. The new track was opened in 1956 and in 1960 the first Armstrong 500 production car race was held at the circuit. Extensive damage resulted from the running of the 1962 Armstrong 500, and, with the circuit owners unable to finance repairs, the circuit was closed and the race was moved to the Mount Panorama Circuit at Bathurst in New South Wales, to eventually become known as the Bathurst 1000.