Emir Zade mosque, former mosque and museum in Chalkida, Greece

The Emir Zade Mosque is a single-dome Ottoman mosque in Chalcis, almost intact apart from its lost portico and minaret. A rectangular prayer hall is covered by a dome hemispherical inside and octagonal outside, resting on four semi-conical domes. A columns gallery, the revak, stands on the west side, and only the square base of the cylindrical minaret remains.

Built shortly after the Ottoman capture of Euboea in 1470, the mosque stood inside Chalcis's fortifications on the site of an earlier church, possibly dedicated to Saint Mark or Saint Paraskevi. Evliya Çelebi, visiting in 1667–1669, counted it among the city's eleven mosques. It was probably rebuilt in the first half of the 18th century; after 1821 it served as a barracks and hay store, and its portico and minaret were lost in the mid-19th century.

The mihrab in the east wall keeps traces of its original polychromy, and two marble plaques with Quranic excerpts in Arabic crown the arch. The entrance frame's marble slabs carry an Arabic inscription asking visitors to enter in peace. The fountain in the yard, built in 1655 by Khalil Pacha and repaired in 1796, bears embossed Arabic inscriptions.

The former mosque is not open to the public: since the 1950s it has housed part of Chalcis's medieval archaeological collection, and a 2013 renovation turned it into an exhibition space holding Ioannis Karakostas's print collection. The building stands inside the walled town of Chalcis, on Euboea; the Ottoman fountain of 1655, moved to the forecourt in 1960, and the column fragments in the yard can be seen from outside.

The courtyard fountain was built in 1655 by Khalil Pacha and repaired in 1796; it was moved to its present spot in 1960. The marble entrance frame carries an Arabic inscription asking visitors to enter in peace, and two plaques with Quranic excerpts crown the arch.