The Diocese of Zella () is a suppressed and titular see of the Roman Catholic Church. The diocese of Zella, is located in today's Tunisia.
During the Roman Empire the Diocese was centered on a Roman town of the Roman province of Byzacena. During late antiquity the city had both a Donatist and Catholic congregation. These two both sent bishops to the Conference of Carthage of 411.
Today Zella survives as a titular bishopric and the current archbishop, personal title, is Samuele Sangalli, who is Adjunct Secretary of the Dicastery for Evangelization.