Agios Nikolaos, Hagios Nikolaos or Aghios Nikolaos is a coastal city on the Greek island of Crete, lying east of the island's capital Heraklion, north of the city of Ierapetra and west of the city of Sitia.

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.