A thirsty koala has been photographed sitting on a bicycle wheel as it drinks from a cyclist's water bottle in the Adelaide Hills region.

Passing cyclist Nick Lothian stopped to take a happy snap of the unusual scene yesterday afternoon.

The koala was still drinking on his return journey 30 minutes later, he said.

Fauna Rescue volunteers later arrived to collect the one-year-old female marsupial.

She spent the night recovering at the Adelaide Animal Hospital.