The Alabama River, in the U.S. state of Alabama, is formed by the Tallapoosa and Coosa rivers, which unite about six miles above Montgomery.

It flows west as far as Selma, then southwest until, about 45 miles (72 km) from Mobile, it unites with the Tombigbee to form the Mobile and Tensas rivers, which discharge into Mobile Bay.

The course of the Alabama is tortuous. Its width varies from 200 to 300 yards (200 to 300 m), and its depth from 3 to 7 feet (1 to 2 m). Its length as measured by the United States Geological Survey is 312 miles (502 km), and by steamboat measurement, 420 miles (676 km).

The river crosses the richest agricultural and timber districts of the state, and railways connect it with the mineral regions of north central Alabama.

The principal tributary of the Alabama is the Cahaba River about 200 miles (300 km long, which enters it about 10 miles (16 km) below Selma. Of the rivers which form the Alabama, the Coosa crosses the mineral region of Alabama, and is navigable for light-draft boats from Rome, Georgia (where it is formed by the junction of the Oostenaula and Etowah rivers) to about 117 miles (188 km) above Wetumpka (about 102 miles below Rome and 26 miles (42 km) below Greensport), and from Wetumpka to its junction with the Tallapoosa; the channel of the river has been considerably improved by the federal government.

The navigation of the Tallapoosa river which has its source in Paulding County, Georgia, and is about 250 miles (400 km) long, is prevented by shoals and a 60 foot (18 m) fall at Tallassee, a few miles north of its junction with the Coosa. The Alabama is navigable throughout the year.