Gallus was born into the gens Annia and was a member of the venerable family of the Annii Regilli.
[1] He was the son of Appius Annius Trebonius Gallus, consul in 108, and an unnamed noblewoman.
[3][4] Tertulla bore him two children: Aspasia Annia Regilla and her husband had built an outdoor monument called an exedra at Olympia, Greece, featuring statues honoring their various relatives and members of the ruling imperial family.
Among the statues was one of a toga-wearing Annius Gallus, which survives without its head, and is on display at the Archaeological Museum of Olympia.
[5] Media related to Appius Annius Trebonius Gallus (consul suffectus) at Wikimedia Commons