Zakynthos (also spelled Zakinthos) is a Greek island in the Ionian Sea. It is the third largest of the Ionian Islands. Zakynthos is a separate regional unit of the Ionian Islands region, and its only municipality. Its coastline is roughly 123 km (76 mi) in length. The name, like all similar names ending in -nthos, is pre-Mycenaean or Pelasgian in origin. In Greek mythology the island was said to be named after Zakynthos, the son of the legendary Arcadian chief Dardanus.

Zakynthos is a tourist destination, with an international airport served by charter flights from northern Europe. The island's nickname is "the Flower of the Levant", bestowed upon it by the Venetians who were in possession of Zakynthos from 1484 to 1797.

Famous landmarks include the Navagio beach, a cove on the northwest shore isolated by high cliffs and accessible only by boat. Numerous natural "blue caves" are cut into cliffs around Cape Skinari, and accessible only by small boats. Keri, on the south of the island, is a mountain village with a lighthouse. The whole western shore from Keri to Skinari contains rock formations including arches.

Northern and eastern shores feature numerous wide sandy beaches, some of which attract tourists in summer months. The largest resort is Laganas. Marathonissi islet (also known as "Turtle Island") near Limni Keriou has tropical vegetation, turquoise waters, beaches, and sea caves. Bochali hill above the Zakynthos town contains a small Venetian castle.