E. De Felice notes that the surname has as its base the name of Germanic origin Ansaldo, formed from ans- ("divinity, god of the Germanic religion") and walda- ("power, powerful"), with the original meaning of "divine power" or "powerful by divine will". He specifies that it was introduced to Italy by the Lombards and re-spread by the Franks, and that it is very frequent in documents of the 10th and 11th centuries in the Latinised forms Ansaldus and Ansaldonus.

De Felice adds that it is widespread in the -s- forms in north-central-western Italy, and in the -z- forms from the Naples area to Sicily.

A. Bongioanni relates the name to the Germanic Ansowald and the Anglo-Saxon Oswald. He notes that the Piedmontese form Assauto arises by phonetic assimilation, and that the Lombard change a > o explains the forms Soldi and Soldini.

V. Blunda, for the Sicilian variant, derives it from the Germanic compound Ans Walda, meaning "divine ruler" or "the one who commands on behalf of the gods", formed from ans ("Ásatrú divinity") and walda ("power, government, command"). He notes that it combines two elements of great prestige in Lombard culture: sacredness of origin and the exercise of political power. He adds that the variant Anzaldo, with voicing of the sibilant, is peculiar to the Sicilian dialect.