Firefighters were called to the blaze on Ash Crescent at around 4.20am.
Police confirmed the man and the girl died as a result of the fire.
A 35-year-old woman and a 13-year-old girl were taken to hospital for treatment to non-life threatening injuries.
They have since been discharged and are being cared for by relatives.
Chief Superintendent Mabs Hussain, District Commander of Wakefield Police, said: “This is clearly a very serious and tragic incident in which a man and a young girl have lost their lives.
“Their family are absolutely devastated by what has taken place and we are working to support them in any way we can.
“This fire will clearly cause great shock to residents in the Stanley area and more widely across the district and our local NPT officers are in the area to speak with people.
“We are working closely with the fire service to determine the cause of this fire and those enquiries are at an early stage.
“I ask anyone in the Ash Crescent or wider area who has information about the fire to contact police.”
Anyone with any information should contact police on 101 or the independent crime fighting charity Crimestoppers on 0800 555 111.