A man has been charged with hitting a policeman during a hit-and-run incident in Brisbane's south.

The road policing command officer was operating a speed camera radar at Tarragindi, near the Pacific Motorway off-ramp, about 4.20pm on Sunday when a car ploughed into him.

A police officer has been seriously injured after a hit-and-run on the southside. (File image)

It was alleged the 24-year-old driver was travelling above the speed limit and when the officer stepped out to wave him down, he struck the 57-year-old senior constable.

Queensland Ambulance said the officer suffered leg and hip injuries and was taken to Princess Alexandra Hospital in a stable condition.