The blaze broke out at approximately 4 a.m. in the 7000 block of Sunnybrae Avenue.
More than 30 firefighters worked to knock down the fire in about 17 minutes. The fire was extinguished before it could spread to the house, where authorities say an elderly couple was fast asleep.
Firefighters found the man's body while searching the charred garage. The man's identity was not immediately known.
Fire officials say the garage did not have a functioning smoke alarm or fire sprinklers. Authorities are investigating whether the garage was used as a residential space.
Arson investigators were called to the scene to try and determine the cause of the fire. Authorities estimated the monetary damage from the blaze to be approximately $30,000.