The authors agree that the surname derives from the place name Norcia, a city situated in the Perugia area (Umbria), and in its origin linked to Jewish communities.

E. De Felice notes that it is a Jewish surname whose most diffused form is Norsa in Milan, where old communities of Jews expelled from Norcia in the 16th century settled. The form Norcia as a surname is more sporadic and is recorded mainly in central Italy.

E. Rossoni adds that at Norcia there was a consolidated Hebrew community, and supplies information about the origin of the place name itself: the city was anciently called Nursia of the Sabines, a name that probably reproduced that of the Etruscan divinity Nortia. Rossoni documents a presence of the surname in various areas of Lazio and in the Avellino area.

It should be noted that toponymic surnames of Jewish origin frequently arose as a result of expulsions or forced migrations: the families adopted —or received— as a surname the name of the city from which they came, thus preserving the memory of their place of origin.