The Lackawanna River is a tributary of the Susquehanna River, approximately 35 mi (56 km) long, in northeastern Pennsylvania in the United States. It flows through a region of the northern Pocono Mountains that was formerly a historically significant center of anthracite coal mining in the United States. The lower reaches of the river flows through the urbanized areas of Scranton, which grew around its banks in the 19th century as an industrial center. Its name comes from a Lenni Lenape word meaning "stream that forks."

The river rises in two branches, the West and East branches, along the boundary between Susquehanna and Wayne counties. The branches, each approximately 10 mi (16 km) long, flow south, closely parallel to each other and join at the Stillwater Lake reservoir. The combined river flows southwest past Forest City, Carbondale, Scranton, and Old Forge. It joins the Susquehanna approximately 8 mi (13 km) WSW of Scranton.

By the middle 20th century, the river was severely polluted from mine drainages in its watershed. The decline of industry in the region, as well as federal, state, and private efforts, have led to an improvement in the water quality. The upper reaches of the river are a popular destination for fly fishing for trout. It was designated as one of the American Heritage Rivers in 1997.