The Latin Archbishopric of Patras was the see of Patras in the period in which its incumbents belonged to the Latin Church. This period began in 1205 with the installation in the see of a Catholic archbishop following the Fourth Crusade.

The Principality of Achaea or Principality of Morea was one of the vassal states of the Latin Empire, which replaced the Byzantine Empire after the capture of Constantinople during the Fourth Crusade. It became a vassal of the Kingdom of Thessalonica, along with the Duchy of Athens, until Thessalonica was captured by Theodore, the despot of Epirus, in 1224. After this, Achaea became for a while the dominant power in Greece.