The authors agree that the surname derives from the medieval personal name of Germanic origin Galimberto. E. De Felice specifies that this name comes from the Germanic *Warinberht, of probable Frankish tradition, composed of *warin- ("protection, defence") and *berhta- ("resplendent, illustrious, famous"), with the possible original meaning of "famous and illustrious in the protection of his people".

E. Rossoni broadens the etymological analysis and posits two possible origins: on the one hand, the medieval Germanic name Waliberht, composed of walah ("strange, foreign") and berht ("illustrious, luminous"); on the other, the Frankish name Guilbert (Gilberto), derived from the Germanic Wilberht, formed by wille ("will") and berht ("illustrious, luminous"). Rossoni identifies the surname as clearly Lombard, with a possible presence also in the Reggio Emilia area.

The original form would have been Garimberti, documented from the 10th century in variants such as Garibertus (936), Garivertus (955) and Warinbertus (992), and the present form Galimberti results from a change of r for l. This source also highlights the first documentation of the surname already consolidated in a text of 1525, where a certain Battistino de Garimberti of Longone al Segrino is mentioned, and in 1589 a Dominicho Garimberto appears in a capitular archive of the Duomo of Monza.