The Cyclades (Greek Κυκλάδες) are a Greek island group in the Aegean Sea, south-east of the mainland of Greece; and an administrative prefecture of Greece. They are one of the island groups which constitute the Aegean archipelago. The name refers to the islands around the sacred island of Delos.

The Cyclades comprise about 220 islands, the major ones being Amorgos, Anafi, Ándros, Antiparos, Delos, Ios, Kéa, Kimolos, Kythnos, Mílos, Mykonos, Náxos, Páros, Pholegandros, Serifos, Sifnos, Sikinos, Síros, Tínos, and Santorini (Thira). Most of the smaller islands are uninhabited.

Ermoupolis, on Síros, is the chief town and administrative center of the prefecture.

The islands are peaks of a submerged mountainous terrain, with the exception of two volcanic islands, Milos and Santorini (Thera). The climate is generally dry and mild, but with the exception of Naxos the soil is not very fertile: agricultural produce includes wine, fruit, wheat, olive oil, and tobacco. Cooler temperatures are in higher elevations and mainly do not receive wintry weather. In transportation, the Cyclades is the only prefecture in Greece that is not linked with a state-maintained highway or a highway number. All of the roads in the island complex are secondary or provincial.

Greek nature is extremely varied ranging from snow covered mountains and dense forest inhabited by brown bears, lynx and deer to thousands of sun drenched islands with sandy beaches.

Tourism makes a significant contribution to the nation's income and therefore the tourist infrastructure is quite advanced. There are hotels for every taste and pocket, adventure activities, extended nightlife in all major cities and towns and of course the many museums and archaeological sites this country is world famous for.

Greece has traditionally been one of the most popular tourist destinations on a global basis and each year, particularly in the summer months, the nation's numerous cosmopolitan islands get crammed by millions of international visitors. Unparalleled natural beauties, golden beaches, idyllic sunsets, a legendary nightlife and the world famous Greek cuisine combined with a unique hospitality and an impressively developing tourism infrastructure make Greece an irresistible hotspot for many. The spectacular success of the 2004 Olympic Games boosted the country's international prestige even further and reaffirmed its status as one of the safest places to be. In 2004, Greece ranked 12th in terms of international tourist arrivals when more than 14.2 million visitors came to the country, many of which combining both vacations and attendance of Olympic athletic events. In 2005, however, those numbers increased by 14%, surpassing 16.1 million arrivals. In 2006, those figures are only expected to grow bigger.