Just before 1am, police and fire crews were called to Plaitford Street at Elizabeth Vale after black smoke was reported coming from a house.
Firefighters quickly extinguished the fire before it could spread to an adjoining property.
No one was injured.
Police say the fire was believed to have been deliberately lit.
Neighbours say a mother and four children left the property earlier this week, 9News reports.
Early today, witnesses described how her partner returned to the property and allegedly started the fire.
Fire cause investigators are attending the scene this morning.
Anyone with information on the fire or saw anything suspicious in the street is asked to contact Crime Stoppers on 1800 333 000.