The 2018 Adelaide 500 was a motor racing event held on the weekend of 2 to 4 March 2018 at the Adelaide Street Circuit in Adelaide, South Australia. It marked the twentieth running of the Adelaide 500 and was the first event of sixteen in the 2018 Supercars Championship. It comprised two races of 250 kilometres. Support races included the opening round of the 2018 Super2 Series, a series for older model Supercars and the inaugural round of the new SuperUtes Series.

The Adelaide 500 is an annual motor racing event for Supercars held on the streets of the east end of Adelaide, South Australia between 1999 and 2020 and again from 2022. The event uses a shortened form of the Adelaide Street Circuit, the former Australian Grand Prix track. The event is still colloquially known as the Clipsal 500 or simply "Clipsal" after its former longtime sponsor. By attendance and number of events, the Adelaide 500 is the biggest multiple-day car race in Australia.