Police Scotland have closed High Street and Scott Street while firefighters tackle the blaze.
Scottish Fire & Rescue Service were called at 9.50am, four appliances and a height unit from Perth were sent to the scene.
A spokesperson from Police Scotland said: “High Street and Scott Street in Perth are currently closed to traffic and pedestrians due to a building fire, reported shortly after 9.50am today.
“Emergency services are at the scene and we would urge people to avoid the area at this time.”
