Scholars agree that this surname, together with its variants Larussa, La Rossa, and Larossa, derives from nicknames based on physical characteristics — in particular the reddish color of the hair or complexion — or on references to a locality of origin ("those of the red house"), possibly alluding to the mother of the first bearer of the surname. It is also recorded simply as deriving from the nickname rosso, meaning "red," to indicate someone with red hair.

V. Blunda specifies that this is a Sicilian surname of dialect origin, stemming from the phrase la rùssa, meaning "the red-haired woman" or "she of the reddish hair." He notes that this trait, unusual among the Mediterranean population, generated lasting nicknames that could become fixed as transmissible family bynames.

E. Rossoni places La Russa as proper to Sicily, while locating the variant Larussa in the area of Catanzaro, La Rossa in coastal Campania and the area of Potenza, and Larossa mainly in Filiano, also in the area of Potenza, with a lesser presence in the area of Foggia.

F. Miranda adds that the surname has two main areas of concentration, in Sicily and Lombardy, with a more modest presence in Calabria, Tuscany, Piedmont, Lazio, Veneto, and Emilia-Romagna. In Sicily it is documented in the areas of Palermo, Agrigento, Catania, Trapani, and Enna.