The surname Racca is typically Piedmontese, native of the Cuneo area, and could derive from the medieval name of Germanic origin Racha, in turn derived from Ragwald, composed of the terms ragin ("counsel, assembly") and wald ("government"). A derivation from an abbreviated form of names such as the Gothic Racharedus is also possible.

In the old local Piedmontese language, racca could be associated with a word that designated a type of vessel or container, which would be consistent with the craft tradition of the region, especially in work with ceramics and metals. It is not ruled out, then, that the surname could have referred in the past to lesser-known or now-vanished trades.

Other surnames of similar spelling have different origins. Racana, Racano, Racar, Rakar and Raccar come from the Gorizia area (Raccaro, very rare, is native of Udine); they are of Slovenian origin and probably derive from the surname Rakar, from the Slavic term rak ("crab"), referring to the occupation of catcher of freshwater crabs. Racana, very rare, is native of Potenza (Lucania). Racano has a presence in the Chieti area —especially in Vasto and Fresagrandinaria— and in the region of Apulia, in the Foggia area (San Severo and Foggia) and in the Bari area (Acquaviva delle Fonti, Cassano delle Murge and Palo del Colle). These last are believed to derive from the archaic Arabic term rahan ("to grind"), which probably indicates miller ancestors.

V. Blunda, for the Sicilian variant, derives it from the Germanic personal name Rac, a Lombard anthroponym linked to an onomastic base of disputed etymology, possibly connected to a hypocoristic form of anthroponyms compounded on roots such as rad ("counsel") or ragin ("divine counsel"). He notes that the consonant doubling -cc- is characteristic of Italian anthroponymy, where it marks affectionate or intensive forms of the original name. As a surname it is preserved in alpine areas of Piedmont and Lombardy, where Germanic anthroponymy formed a dense onomastic substrate from the Lombard period to the late Middle Ages.