Lesbi, a titular see in Mauretania Sitifensis, suffragan of Sitifis, or Setif, in Algeria. It is not, as is sometimes stated, the island of Lesbos, which never was a titular bishopric and which, moreover, possesses two titular archbishoprics: Mytilene and Methymna. Of Lesbi we only know, from the “Itinerarium Antonini”, that it was situated twenty-five miles from Tupusuctu or Tiklat, and eighteen miles from Horrea Aninici, now Ain-Roua, south of Bougie. The town, therefore, was on the Sava, i.e. the Oued-Bou-Sellam, but there are no remains to be seen. Two of its bishops are recorded: Romanus, a Donatist, present at the convention of Carthage, 411; Vadius, a Catholic, exiled by King Huneric, 484.