Hamza Bey Mosque (Greek: Αλκαζάρ Θεσσαλονίκης, Turkish: Hamza Bey Camii) is a 15th-century Ottoman Mosque in Thessaloniki, Greece.

[1] Modern Thessalonians commonly known it as Alkazar, after a cinema that operated in the premises for decades.

It initially housed various military services, and although it was declared a protected monument in 1926, it was sold in 1928 to private owners.

The building was subsequently used for several decades as a cinema, and suffered extensive modifications.

The mosque was handed over to the Greek Ministry of Culture in 2006, and restoration work has been under way since.