The diocese of Mibiarca (in ) is a suppressed and titular see of the Catholic Church, in today's Tunisia. It is an ancient episcopal seat of the Late Roman province of Byzacena.
The only known bishop of this African diocese was John, who participated in the anti-monotheistic council of Carthage (641).
Today Mibiarca survives as a titular diocese established in 1933. Its initial bishop was Marcelo Gérin y Boulay, the Prelate of Choluteca in Honduras, who was appointed in 1966. The current titular bishop is Thomas Padiyath, who was appointed in 2022 and who is an auxiliary bishop of the Syro-Malabar Eparchy of Shamshabad in India.