Two adults and a child were found unconscious inside the property on Wharfe View, Pool-in-Wharfedale, near Otley late last night.
One of the adults, a man, was rescued by neighbours and was suffering from 25 per cent burns to his body.
District Commander for Leeds Russ Hepton said: “The actions of the neighbours are truly courageous. They have entered the house despite there being a serious and developing fire inside, without prioritising their own safety. They came across the man, who has suffered serious burns, and were able to get him outside to safety.
Neighbours also guided the fire engines into the scene and crews acted swiftly to rescue the woman and child and gave them oxygen at the scene to assist their breathing.”
Firefighters from Otley, Rawdon and Cookridge were called to reports of people trapped inside the burning building just after 10.50pm and when they arrived they entered the property to recover a woman and a child.
They used two hose reels, four breathing apparatus and a high-powered ventilation fan. A fire investigation officer was also called to the scene.
A smoke detector was found to be installed inside the property but it was not working.
Acting Detective Inspector Mark Atkinson, of Leeds District CID, said: “At 10:55pm last night, police were contacted by the fire service who were attending a fire at a house in Wharfe View, Pool-in-Wharfedale.
“A 51-year-old man had been helped from the property by neighbours, and a 41-year-old woman and a nine-year-old girl were brought out from upstairs by firefighters. All three were given emergency treatment at the scene by firefighters and paramedics before being taken to hospital.
“The man received burns and is currently in a serious condition in Pinderfields Hospital. The woman and child were taken to Leeds General Infirmary for treatment for smoke inhalation and their conditions are not believed to be life threatening.
“We are not treating the incident as suspicious but are continuing to work with fire investigators to establish the full circumstances.”
All three casualties were transported to hospital by ambulance.
An investigation into the cause of the fire is ongoing today.