The blaze was reported at 4:26 a.m. at 1335 Montecito Ave. and was brought under control at about 6:10 a.m., a fire dispatcher said.
The fire appears to have started in a vehicle parked in a first-story carport and run up the structure's wall, according to Mountain View Fire Department spokesman Lynn Brown.
The apartments were evacuated and no injuries were reported, Brown said.