a Roman general under the emperor Otho in his expedition against the troops of Vitellius, in A. D. 69. He was sent out by Otho to occupy the banks of the Po; and when Caecina laid siege to Placentia, Annius Gallus hastened with a detachment of his army to the relief of the place. When Otho assembled his council, to decide upon the mode of acting, Eallus advised him to defer engaging in any decisive battle. After the defeat of Otho's army in the battle of Bedriacum, Annius Gallus pacified the enraged Othonians. In the reign of Vespasian he was sent to Germany against Civilis. (Tac. Hist. 1.87, 2.11, 23, 33, 44, 4.68, 5.19; Plut. Otho 5, 8, 13.)