Regina fire says the blaze began in one home in the 1700 block of Toronto Street at about 12:30 a.m., and spread to the neighbouring homes.
The house in which the fire started was mostly destroyed according to acting deputy fire chief Glenn Wagner, while the flames spread to the attic in another home causing significant damage.
He said the third home received minor damage to the outside panelling.
Wagner said five fire trucks and about 20 firefighters were on scene and that it took about three hours to put the fire out.
He said the residents of the three homes were outside when fire crews arrived and nobody was injured.
Investigators are still working to find the cause of the fire and the cost of the damage.