The authors agree that this surname derives from a given name of Germanic origin, formed from two elements: a root meaning "illustrious" or "famous", and another meaning "combat" or "fighter". A. Bongioanni identifies those roots as hlod/hlud ("illustrious") and wig ("to fight", "fighter"), and explains that in the Frankish dialect the aspirate turns into a guttural, giving the Latin forms Clodovicus and Clodoveus, the German Ludwig and the Old French Loois and Louis. V. Blunda, for his part, reconstructs the compound as Wlod Wig, with the sense of "famous combat" or "glorious struggle".

Bongioanni notes that the French and the Germanic forms passed early into Italy: in Venice the name became Alvise, later Latinized as Aloisius and Aloysius. As a surname coming directly from Ludovico he records Luígo in Veneto, Ludovisi in central Italy, and the forms Dovico, Davicò and Dovis in Piedmont. From Alvise derive Alvisi, Alvisini, Visetti, Visocchi and Lovisato, among others, as well as the hybrid Piedmontese forms Aluigi and Alluigi.

Blunda adds that the variant Luigi reflects the phonetic evolution of the Germanic name into modern Italian, where the loss of internal consonants gave rise to the present form of the masculine name, and stresses the figure of Saint Louis IX of France as the model of the medieval Christian king, which contributed to the spread of the name in the Middle Ages.