Gaidoald (Latin: Gaidoaldus) was the second Lombard Duke of Trent. He was assigned to Trent on the death of Euin in January 595. He was described by Paul the Deacon as "a good man and a Catholic in religion" in his Historia Langobardorum. In 602 or 603, Gaidoald and fellow duke Gisulf I of Friuli made peace with king Agilulf in what Paul the Deacon refers to as a "year of peace". No dukes of Trent are known after Gaidoald until Alahis from 680 to 690.
- Paul the Deacon (1907), History of the Langobards (Historia Langobardorum), William Dudley Foulke, trans. (Philadelphia: University of Pennsylvania), IV, x.
- Paul the Deacon, IV, xxvii, is not clear whether this event is to be connected with the death of the Byzantine emperor Maurice in 602 or the baptism of the Lombard prince Adaloald on 7 April 603 (which it preceded).