Caspian terns have a cosmopolitan distribution, they are found on all continents except Antarctica. They are found along coastlines of oceans, seas, large lakes, and rivers. They migrate between breeding and wintering ranges for the most part, although some populations are resident year-round. (Cuthbert and Wires, 1999)

 

In the Americas, Caspian terns breed along coastal and inland waterways from the Gulf of Mexico and Baja California northwards through the Great Lakes and Canadian interior and as far north as southern Alaska on the Pacific coast and the Canadian maritime provinces on the Atlantic coast. They winter from southern California to Guatemala along the Pacific coast, including the Gulf of California, and from southern North Carolina on the Atlantic coast to Panama and Venezuela, including the Gulf of Mexico. They also winter in the Antilles. (Cuthbert and Wires, 1999)

 

Caspian terns breed in coastal areas from Scandinavia to the Baltic and Black Seas, throughout central Asia to Mongolia and the Persian Gulf and Red Sea to southeast Asia. They also breed throughout Australasia and Africa. Winter ranges are in warmer areas of their breeding range, including the Baltic, Black, and Mediterranean Seas, the Persian Gulf, and along African coastlines to South Africa. (Cuthbert and Wires, 1999)