The Mehmet Bey Mosque (Greek: Τέμενος Μεχμέτ Μπέη), locally also known as Hagia Sophia (Αγιά Σοφιά), is a 15th-century Ottoman mosque in the city of Serres in northern Greece. The mosque was built by the eponymous Mehmet Bey in 1492–93. Mehmet was a son-in-law of Sultan Bayezid II, having married the princess Selcuk Hatun. The couple lived in the city in the late 15th century and endowed it with several other buildings, none of which survive. It had already fallen out of use by the late 19th century, when it was severely damaged by floods of the nearby stream of Agioi Anargyroi.