Police are investigating the vandalism in College Street, which happened at about 9.30 pm.
Windows were smashed and wing mirrors broken on a Honda Jazz car, a Renault Dispatch van, a Honda Civic car, a Mercedes car and a VW Golf car.
A window was also smashed on a lorry which was parked within the fairground on the Whitesands.
Constable Ruairidh Matthews at Dumfries said: “This is yet another example of wanton vandalism to vehicles in Dumfries which will cost the owners a lot of money and inconvenience.
“We are appealing to the public to help us catch those responsible and ask that anyone who has any information which might help to get in touch with us at Dumfries on 101.”