principal tributary of the Chari (Shari) River of the Lake Chad Basin, draining northeastern Cameroon and Chad. It is formed by the Mbéré River and its tributary the Vina (Wina, Mba, Bini) of northern Cameroon and by the Pendé of northwestern Central African Republic. The two headstreams join 28 miles (45 km) south-southeast of Laï, Chad, to form the Logone, which then flows 240 miles (390 km) northwest to N'Djamena, Chad, and combines with the Chari.

There are extensive papyrus swamps and marshes along much of the Logone. During the rainy season, it is linked to the Benue River system through the Lake Fianga and Tikem swamps (Chad) and the Mayo Kébi River in Cameroon. The regular loss of a portion of Lake Chad's water supply to the Benue system is a serious problem for the arid region. The Logone is seasonally navigable below Bongor, Chad, for small steamers and provides rich fishing grounds.