Police are investigating the armed robbery of a pizza delivery driver in Noosa overnight.

Just before 10pm, the 19-year-old male driver was making a delivery at a Grant Street address when he was flagged down by another man.

As the driver was attempting to hand over the delivery, the man threatened him with a knife and fled the scene with cash and the pizza.

No one was physically harmed during this incident.

The offender is described as being in his early 20s, Caucasian in appearance, of average build and around 185cm tall.

He was wearing board shorts, no shirt and was also without shoes. He has a tattoo on his left arm and a silver lip ring in his bottom lip.