Optatus, a Donatist bishop of Thaumugade in Numidia, was called Gildonianus from his adherence to Gildo, Count of Africa, and generalissimo of the province under the elder Theodosius. On his death, in 395 A.D., Gildo usurped supreme authority, and by his aid Optatus was enabled to oppress the Catholics in the province, till, in 398 A.D., Gildo was defeated by his brother Maxezel, and destroyed himself, and Optatus was put in prison, where he died soon afterwards. He is not to be confounded with Optatus, Bishop of Milevis, the strenuous opponent of the Donatists.