Arson squad are investigating the blaze.
Authorities said fire ripped through a home in Commercial Road in Forrestdale around 3am on Saturday.
Sixteen firefighters attended the scene to extinguish the blaze.
One man was found deceased at the scene, it's believed he was inside the structure during the time of the blaze.
Arson squad will investigate the cause of the fire today.
Scorching Christmas temperatures for Perth, Rockingham, Mandurah
Teen charged over Baldivis arson attack
Concerns for missing boy last seen in Warnbro
Baldivis Sports Complex officially complete with unveiling of final stage
Teen dies at Logue Brook Dam
Mandurah named WA’s Most Accessible Community
Police attend separate crashes in Lakelands and Port Kennedy
Fresh new look for Roger May Machinery Museum
Tragic end to search of missing FIFO worker