Kissamos is a town and a municipality in the west of the island of Crete, Greece. It is part of the Chania regional unit and of the former Kissamos Province which covers the northwest corner of the island. The town of Kissamos is also known as Kastelli Kissamou and often known simply as Kastelli after the Venetian castle that was there. It is now a port and fishing harbour, with a regular ferry from the Peloponnese via Kythira. A town museum is located in the old Venetian governor's palace and there have been important archaeological finds in the town, including fine mosaics, dating from the Roman city of Kisamos. The head town of the municipality is Kastelli-Kissamos itself.

Crete is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, and Corsica. Crete rests about 160 km (99 mi) south of the Greek mainland, and about 100 km (62 mi) southwest of Anatolia. Crete has an area of 8,450 km2 (3,260 sq mi) and a coastline of 1,046 km (650 mi). It bounds the southern border of the Aegean Sea, with the Sea of Crete to the north and the Libyan Sea to the south. Crete covers 260 km from west to east but is narrow from north to south, spanning three longitudes but only half a latitude.