Police are on the hunt for a cyclist who punched a female bus driver in the face at Tarragindi.

The male bike rider approached the bus near the intersection of Toohey Road and Weller Road yesterday about 10.20am.

When the bus driver opened the door, he attempted to start an altercation, according to police.

"The man then punched the bus driver several times in the face and arms before leaving the bus and riding away inbound on Toohey Road," police said in a statement.

The driver was not seriously injured.

Police say the man is described as Caucasian with tanned skin, between 165 and 175cm tall, aged between 25 to 30-years-old, with a slim athletic build.

He was wearing a red lycra short sleeve shirt with a lighter coloured strip along the back, silver bike shorts and a helmet.

Anyone with information should contact Crime Stoppers: 1800 333 000