Osmaniye Mosque, Chios, mosque in Greece

The Osmaniye Mosque is a rectangular Ottoman building in the old citadel of Chios town, with a floor plan of 8 by 10 metres and a main prayer hall of 8 by 8 metres. It has a roof-floor, an entrance portico and a gallery on the west side giving access to the minaret. The octagonal minaret stands at the northeastern corner, next to a historical Turkish outbuilding that held service rooms.

The mosque was built in 1891-1892 on the orders of Sultan Abdülhamit II during Ottoman rule of Chios. Following the Greek capture of the island in 1912, it ceased functioning as a place of worship and was later repurposed for cultural uses.

The mosque is locally known as the Frangomachala Mosque, a name referring to the former Frankish quarter and reflecting the island's multicultural past. This name reveals how different communities once coexisted and practiced their beliefs in this area of the citadel.

The mosque stands in the old citadel area of Chios town, the former main quarter of the island's Turkish community, where two other mosques also survive. Since its 1997 renovation the building has served as a venue for exhibitions and cultural events rather than worship, so it is seen from inside during such functions. The minaret rises at the northeastern corner, reached by a gallery on the west side.

The mosque is one of only three surviving mosques on Chios, standing in the old citadel area that was the main neighbourhood of the island's Turkish community. Its minaret is octagonal and rises from the northeastern corner, with a gallery on the west side giving access to it. A separate historic Turkish building attached to the minaret once held service rooms.