Police are investigating a deliberately lit structure fire in Devonport overnight.

Emergency services were called to the scene on Gunn Street about 1am, arriving to find the unoccupied residence well alight.

Multiple units from Tasmania Fire Service attended and extinguished the fire. The building was significantly damaged.

Fire investigators have determined it was deliberately lit.

Police are investigating the circumstances of the fire and would like to speak to anyone who may have witnessed the fire, or anyone acting suspiciously nearby at the time.

Information can be provided to Devonport Police on 131 444 or Crime Stoppers at crimestopperstas.com.au