These are surnames that may derive from place names such as Gualtieri (Reggio Emilia area) or Gualtieri Sicaminò (Messina area), as well as from the Norman name Gualtier or the Latin cognomen Gualterus.

Another hypothesis derives Gualtieri directly from the Germanic personal name Waltheri, from the Lombard Walthari or Waldari, with the meaning "mighty in the army" (from the Germanic waldaz, "mighty" or "chief", and harja, "army"), Latinized as Gualterius. The given name Walterius is documented in charters from Modena from 1118 onwards. Gualteri, very rare, would appear to be from the Cremona area. Gualtieri is found throughout the peninsula.