The Ogooué, also known as the Nazareth River, some 1,200 km (750 mi) long, is the principal river of Gabon in west-central Africa and the fourth largest river in Africa by volume of discharge, trailing only the Congo, Kasai and Niger. Its watershed drains nearly the entire country of Gabon, with some tributaries reaching into the Republic of the Congo, Cameroon, and Equatorial Guinea.

Gabon, officially the Gabonese Republic, is a country on the Atlantic coast of Central Africa, on the equator, bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo on the east and south, and the Gulf of Guinea to the west. It has an area of 270,000 square kilometres (100,000 sq mi) and a population of 2.3 million people. There are coastal plains, mountains, and a savanna in the east. Libreville is the country's capital and the largest city.