The authors agree that the surname derives from medieval hypocoristic forms, mainly Tore and Torello, though they differ as to their base etymons. R. Brondolo proposes that it refers to Vittore or Vittorio, through the aphaeretic form (Vit)torelli, and also notes an alternative hypothesis that connects it with an auspicious diminutive of (Bona)ventura, associated with the idea of good luck. E. Rossoni broadens this list and includes names such as Salvatore, Nestore and Astore, all of them with the loss of the initial syllable. Rossoni also incorporates a possible toponymic derivation from places such as Masi Torello, in the Ferrara area, or Torella del Sannio, in the Campobasso area, among others.

Rossoni also documents the Latin form Taurellus —"little bull"— in texts of the Modena area of the year 1159, which suggests that in some cases the surname could have originated as a nickname referring to the animal. The suffix -elli is considered to fulfil a diminutive or familiar function, and indicates descent from an ancestor called Tore or Torello. The surname is diffused throughout peninsular Italy, with a presence documented especially in Emilia-Romagna, Tuscany, Lombardy and Lazio.