Niccioleta is a village in Tuscany, central Italy, administratively a frazione of the comune of Massa Marittima, province of Grosseto, in the area of the Colline Metallifere. At the time of the 2001 census its population amounted to 248.Niccioleta is about 54 km from Grosseto and 5 km from Massa Marittima, and it is situated on a hill rich of mines of calamine and pyrite. The town is known for the slaughter of civilians performed by the fascists between 13 and 14 June 1944.