Fire crews fought until the early hours to bring a blaze under control after it broke out at the vacant Priory Campus in Kirkcaldy on Monday night.
Two fire crews from Kirkcaldy station as well as appliances from Burntisland and Glenrothes stations were sent after the alarm was raised shortly before 9pm.
The blaze started on the third floor of the derelict former accommodation building directly behind Nairn Mill in High Street, which until 2016 had been used by Fife College.
The site had has been a magnet for anti-social behaviour and vandals since the campus closed.
A spokesperson for Scottish Fire & Rescue Service said: “We received the call at 8.46pm on Monday of a fire at the Nairn Building in High Street Kirkcaldy.
“Two fire crews including a high reach appliance were sent from Kirkcaldy station and on arrival crews found the building well alight.
“The fire had started on the third floor of the property.”
The spokesperson added: “Two further appliances, one from Burntisland and another from Glenrothes, were also sent to assist.
“Fire crews tackled the blaze mainly from the exterior of the building as well as using the high reach vehicle.
“No persons were injured in the incident.
“The stop sign was given at 1am when crews left the scene.”
A planning application to turn the vacant Nairn Building, which sits adjacent to where the fire broke out, into flats and a gym was approved in December.