Thaumastus (born c. 400) [1] was a friend and uncle of Sidonius Apollinaris.
His brother, the elder Apollinaris was born around 405 [2] and was the praetorian prefect of Gaul under Valentinian III between 425 and 455. [3] Thaumastus and his brother were both sons of another Apollinaris, praetorian prefect of Gaul before 409 [3] and were friends with his successor Decimus Rusticus. Thaumastus was associated with Tonantius Ferreolus in the impeachment of Arvandus. [4] He was the father of Eulalia, born in 425, [2] married before 450 to Probus, Roman Senator.
He seems to be a descendant of yet another Apollinaris, praetorian prefect of Gaul under Constantine II between 337 and 340. [3]