The university’s Nuon Solar Team was the first to arrive at the finish line in Adelaide. The 3,000km (1,800 mile) race took four days to complete.
The race, which happens once every two years, started on Sunday in Darwin.
Nearly 50 teams from universities and schools around the world took part. Delft University had also won the last challenge in 2013.
The World Solar Challenge is aimed at promoting research on solar-powered cars which could become a consumer product one day.
In second place was a team from the University of Twente, also from the Netherlands; while Japan’s Tokai University came in third.