The Green River is a tributary of the Ohio River that rises in Lincoln County in south-central Kentucky.

In 1842, Kentucky's Green River was canalized, with a series of locks and dams being built to create a navigable channel as far inland as Bowling Green, Kentucky. Four Locks and Dams were constructed on the Green River, and one Lock and Dam was built on the Barren River, a Green River tributary that passed through Bowling Green.

In 1901, two additional Locks and Dams were opened on the Green River, which allowed river traffic to Mammoth Cave, KY. In 1941, the Mammoth Cave National Park was established, and the two upper locks and dams closed in 1950. In 1965, Lock and Dam #4 at Woodbury Kentucky failed; this being the dam that locked both the Green and Barren rivers.

The 300-mile long Green River, an important transportation artery for the coal industry, is open to traffic up to the closed Lock and Dam #3 at mile 108.5. Muhlenberg County, once the largest coal-producing county in the nation, benefits greatly from access to the river as does the aluminum industry in Henderson County . In 2002, more than 10 million short tons were shipped on the river, primarily lignite coal, petroleum coke and aluminum ore.

Tributaries include Barren River, Nolin River, Pond River and Rough River.

This Green River should not be confused with the Green River in Wayne County in south central Tennessee, which is a tributary of the Buffalo River.