Fire crews were called around 4:30 a.m. to the Club House Diner, located on the 2400 block of Street Road in Bensalem.
Firefighters brought the blaze under control in less than 30 minutes, containing the flames to the roof area.
No injuries were reported.
The Bucks County Board of Health was called to the scene to review the condition of the restaurant, giving the all clear for the business to reopen.
The cause of the fire remains under investigation.