The authors present different hypotheses on the origin of this surname. E. Rossoni notes two main possibilities: a derivation from the place name Troia, a locality in the Foggia area documented from 1266, and another coming from nicknames linked to the word troia ("sow"). He documents its presence in zones of Bari, between Rome and Frosinone, in the Naples area, in that of Potenza and in Sicily, besides the variants Troja and Troya.

V. Blunda approaches the surname from a Sicilian dialectal perspective and agrees with Rossoni on the zoonymic etymon: he derives it from the word tròia, "female of the pig", associating it with a nickname related to pig breeding. Blunda expressly clarifies that the interpretation linking it to the Italian troia in the sense of "woman of licentious life" is a false etymology.

R. Brondolo, on the other hand, proposes a different line of interpretation for northern Italy: the surname, still present in the Acquese area, in the south of Piedmont, would seem to relate to the medieval narrative derived from the Trojan cycle, that is, to the literary tradition centred on the Trojan War.