The cover of a car parked in a Daventry driveway was set on fire, causing damage to the vehicle.
The arson happened sometime between 2.10am and 2.50am on Saturday, January 13 in Maritime Way in Southbrook.
A Northamptonshire Police spokesperson said: "The suspect is described as a white man, about 5ft 9in, with a slim build. He was wearing blue jeans, a dark-coloured Nike hooded top with the hood up, and black shoes."
Witnesses or anyone with information are asked to call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.