A pedestrian has been struck by a bus in Sydney's CBD.

Police and paramedics were called to the corner of Pitt and Hay streets in Haymarket at 8.50am on Wednesday to reports that a man had been injured.

A man was hit by a bus on the corner of Pitt and Hay streets. Credit:Sharyn McCowen

A NSW Ambulance spokesman said paramedics were treating a man, thought to be aged in his early 20s, for minor head injuries. He is expected to be taken to hospital.

A NSW Police spokeswoman confirmed police were at the scene, but the circumstances of how the crash occurred were not known.