Cinque Ports (French: "Five Ports"), medieval confederation of English Channel ports in southeastern England, formed to furnish ships and men for the king's service. To the original five ports - Hastings, New Romney, Hythe, Dover, and Sandwich - were later added the "ancient towns" of Winchelsea and Rye with the privileges of "head ports."

More than 30 other towns in the counties of Kent and Sussex were also attached. Until the 14th century the Cinque Ports provided the permanent nucleus of the royal fleet. They were probably first associated in the reign of Edward the Confessor for the defense of the coast and cross-channel passage. After the Norman Conquest of 1066, their importance grew, and, in return for ship service, their privileges were increased to reach their zenith in the 13th and 14th centuries. They were first jointly granted liberties by charter in 1278.

After the 14th century they lost their monopoly, and, although they continued to contribute to the navy, this function was unimportant by the time of the threat of invasion by the Spanish Armada in 1588. Their decline was accelerated by encroachment by the sea on the coastline and silting at other places, and today only Dover remains an important port. Most of their peculiar jurisdiction was abolished in 1855, and only jurisdiction in Admiralty survives.

In addition to the towns named above, the other members of the confederation (known as limbs) are Lydd, Faversham, Folkestone, Deal, Tenterden, Margate, and Ramsgate, all in the county of Kent. The highest officer of the Cinque Ports is the lord warden, who is also constable of Dover Castle and has Walmer Castle as his official residence.