Tubunae (or Thubunae) was a Roman-Berber city in Algeria. It is believed to have been in either ancient Mauretania Caesariensis and/or Numidia.
There were two towns called Tubunae in the territory of what is now Algeria, when it was part of the Roman Empire. One is referred to as Tubunae in Mauretania, because it was part of the Roman province of Mauretania Caesariensis. The other (the modern town of Tobna) is called Tubunae in Numidia, because it was situated in the Roman province of Numidia. Writers such as Morcelli uses the spelling "Tubunae" for both of them, but the Catholic Church's list of titular sees refers to the second of them (corresponding to modern Tobna) as Thubunae in Numidia.
There it is even the possibility that both names are for the same settlement.
The names of none of the bishops of this town, which is mentioned by Ptolemy, have been preserved. The see was vacant when Huneric summoned the North African bishops to Carthage in 484.
It was to this town "in the depths of Numidia" that Augustine of Hippo and Alypius went, probably in 421, to meet the Roman official Boniface and exhort him "to serve the Church by protecting the empire from the barbarians".
In 479 Huneric exiled a large number of Catholics there. Its ruins, known as Tobna, are in the Department of Constantine, Algeria, at the gates of the Sahara, west of the Chott el Hodna, the "Salinae Tubunenses" of the Romans. They are very extensive, for three successive towns occupied different sites, under the Romans, the Byzantines, and the Arabs. Besides the remains of the fortress, the most remarkable monument is a church now used as a mosque.