E. Rossoni notes that the surname derives from the medieval name Ettore, an Italianization of the Greek Hektor, whose interpretation is etymologically difficult. By tradition it has been associated with the Greek verb echein ("to have, to hold, to govern, to protect"), whence the name is usually translated as "the one who governs and cares for the people". A. Bongioanni agrees on the Greek origin, although he formulates the meaning in a more synthetic way: "possessor" or "tenacious".

V. Blunda adds that the form comes from the Greek Ector, corresponding to the personal name Hector, preserved as a baptismal name in the onomastic tradition of the Mediterranean and fixed as a surname in eastern Sicily through the habitual transmission of Greek personal names until its crystallisation as a family name. P. Durante likewise confirms the Greek origin of the surname, linking it to a proper name.

Rossoni adds that in some zones of southern Italy —concretely in Puglia and Basilicata— it is possible that the variant Ettorre derives from an Albanian or Greek-Albanian origin. As for the geographical distribution, he distinguishes between the two main variants: Ettori presents specific zones in the Brescia area, especially in Villa Carcina and Concesio, as well as in Milan and the Mantua area, with another specific zone in Rome; Ettorre, for its part, appears in the Teramo and L'Aquila area, in Abruzzo, and in another zone between Taranto, Bari and Matera.

Bongioanni also mentions that the family of the forms Ettorei and Ettoreo, documented in Friuli-Venezia Giulia, is extinct.