E. De Felice notes that this surname derives from the name Lotto —documented in Pistoia in 1228 under the form Lottus—, which functioned as a hypocoristic of names ending in -lotto, such as Angelotto, Bertolotto or Michelotto. De Felice considers it sporadic in Italy generally, with a presence concentrated mainly in Tuscany.

E. Rossoni agrees in identifying Tuscany as the main cluster of the surname, but broadens the geographical distribution: he identifies additional areas in the province of Brindisi and in Emilia-Romagna. As for the form Lotto, Rossoni places it especially in Veneto, with a presence between the provinces of Vicenza and Padua and another area in that of Belluno, as well as a native core in Sardinia, in the Villagrande Strisaili area, in the province of Nuoro. Given the independent character of these origins, Rossoni considers that the hypotheses of derivation are multiple, although he favours the one proceeding from the aphaeresis of names such as Paolotto, Lancillotto or Galeotto.