The Roman Catholic Apostolic Vicariate of Thessaloniki (Latin: Vicariatus Apostolicus Thessalonicensis) is an Apostolic Vicariate of the Latin Rite of the Roman Catholic Church in Greece. The Vicariate was established in 1926, comprising the provinces of Thessaloniki, Kavala, Xanthi, Volos, Larisa and Giannitsa.
The Vicariate remains vacant since its only Bishop, Alessandro Guidati, was appointed the Archbishop of the Archdiocese of Naxos, Andros, Tinos and Mykonos in 1929.