The woman's body was recovered from a ground-floor flat in Manor House Close, Moss Side following a fire at 2.50am on Saturday (March 7).
Fire crews from Leyland, Penwortham and Bamber Bridge rushed to the home in a cul-de-sac off Slater Lane, where they were joined by North West Ambulance Service.
After gaining entry to the flat, paramedics attended to a woman casualty, but she was pronounced dead at the scene.
Lancashire Police and the fire service are conducting a joint investigation into the cause of the fire.
A police spokesman said: "We were called around 2.50am on Saturday (March 7) to reports of a fire at a property in Manor House Close, Leyland.
"Emergency services attended with the body of a woman, believed to be in her 50s, found inside the address.
"Sadly she was pronounced dead at the scene.
"The woman's death is not being treated as suspicious and a file will be passed to the coroner in due course."
Firefighters equipped with breathing apparatus were able to extinguish the fire using two hose reels and a fan.
A spokesman for LFRS added: "We were called to a house fire in Manor House Close, Leyland at 2.50am on Saturday, March 7.
"We sent three fire engines to the scene, from Penwortham, Leyland and Bamber Bridge.
"A woman was pronounced dead at the scene by North West Ambulance Service.
"An investigation into the cause of the fire is ongoing."