The fire started along the freeway near MacArthur Boulevard before it spread into evergreen bushes along the parking lot, catching the cars on fire.
A spokesperson for the Oklahoma City Fire Department told News 9 that 13 Chick-Fil-A employees were checked out for smoke inhalation and three taken to a nearby hospital.
All the vehicles that burned belonged to Chick-Fil-A employees.
Firefighters extinguished the fire and prevented further fire spread to the building.