The one-alarm blaze was reported just after 12:30 a.m. at the single-family home at 2431 55th Avenue, said Oakland fire Lt. David Brue.
The flames spread from the first floor to the second floor of the structure before fire crews brought the blaze under control at around 1 a.m.
Brue said 21 firefighters responded to the blaze and preliminary reports indicate the cause to be electrical.
The fire caused an estimated $60,000 of property damage and $30,000 in damage to contents, Brue said.
The American Red Cross responded to provide aid to the displaced.