Halki is a Greek island and municipality in the Dodecanese archipelago in the Aegean Sea, some 9 km (6 mi) west of Rhodes. With an area of 28 km2 (11 sq mi), it is the smallest inhabited island of the Dodecanese. It is part of the Rhodes regional unit. The community is divided in two parts, Chorio (also spelled Horio, "Village") Emporio ("Market").
The island supported a much larger population but following emigration in the mid-20th century Chorio was almost completely abandoned. A sizable group of the residents moved to Tarpon Springs, Florida, establishing the Greek-American community there that continues to this day. A ruined medieval castle of the Knights of St. John overlooks the old town and the chapel contains some of the original frescoes.
The Municipality of Chalki includes several uninhabited offshore islands, the largest of which is Alimia to the northeast, and has a total land area of 37.043 square kilometres (14.302 sq mi). The island's primary industry is tourism, although fishing is also substantial.