No one has been reported hurt in the earthquake, though some damage to churches, convents and other historic buildings has been reported.
The quake hit part of the Apennine mountain range, centering on the Mugello region of Tuscany, some 31 km (19 miles) northeast of Florence.
Screenshot: Google Maps
It hit at 4:37 am after a series of smaller quakes, according to the national institute for geophysics and vulcanology (INGV).
Residents fled their buildings in the rain, congregating outside or in cars to await authorities.
“The quake went on for awhile, especially the first one, things fell down at a supermarket but for the moment we haven't seen any damage to people or things,” said Filippo Carla' Campa, mayor of the town of Vicchio.
A resident of Barberino del Mugello said his neighbours were panicking getting out of the building.
“Paintings fell off the walls, bookcases fell over,” he told Rai 24.
In Barberino del Mugello, the 17th century church suffered a crack in one side, television images showed.
Schools were closed in the region and many trains through Florence were cancelled or delayed n Monday morning.
Italy is frequently struck by seismic activity, often devastating. Most recently, a series of strong quakes hit central Italy in late 2016 and early 2017, killing 300 people.