It happened at about 03:15 BST on Saturday at a house in Austin Drive, Tandragee.
The petrol bomb was thrown at the front of the house and fire fighters were called to put out the blaze.
A man in his 30s and a woman in her 20s who were in the house at the time escaped injury. The kitchen in the house was smoke damaged.
Police are working to establish a motive for the attack. They have appealed for witnesses.
A man and woman have escaped injury in a petrol bomb attack in County Armagh.