The Athabasca River (French: Rivière Athabasca) in Alberta, Canada, originates at the Columbia Icefield in Jasper National Park and flows more than 1,231 km (765 mi) before emptying into Lake Athabasca. Much of the land along its banks is protected in national and provincial parks, and the river is designated a Canadian heritage river for its historical and cultural importance. The scenic Athabasca Falls is located about 30 km (19 mi) upstream from Jasper.

The name Athabasca comes from the Woods Cree word ᐊᖬᐸᐢᑳᐤ aðapaskāw, which means "[where] there are plants one after another", likely a reference to the spotty vegetation along the river.^{[citation needed]}

The Athabasca River originates in Jasper National Park, in Lake Providence at the toe of the Columbia Glacier within the Columbia Icefield, between Mount Columbia, Snow Dome, and the Winston Churchill Range, at an elevation of approximately 1,600 metres (5,200 ft). It travels 1,231 km (765 mi) before draining into the Peace-Athabasca Delta near Lake Athabasca south of Fort Chipewyan. From there, its waters flow north as Rivière des Rochers, then join the Peace River to form the Slave River, which empties into the Great Slave Lake and discharges through the Mackenzie River system into the Arctic Ocean. The cumulative drainage area is 95,300 km² (36,800 sq mi).

The river flows along icefields and through gorges, offering wildlife habitat on its shores and in adjacent marshes. Throughout its course, it flows through or adjacent to numerous national and provincial parks, including Jasper National Park, Fort Assiniboine Sandhills Wildland Provincial Park, Hubert Lake Wildland Provincial Park, La Biche River Wildland Provincial Park, Grand Rapids Wildland Provincial Park, Richardson Wildland Provincial Park, and Wood Buffalo National Park. Its course is marked by rapids, impeding navigation southwest of Fort McMurray.

Numerous communities are on the banks of the Athabasca River, including Jasper, Brule, Entrance, Hinton, Whitecourt, Fort Assiniboine, Smith, Athabasca, Fort McMurray, and Fort McKay.

There are several crossings of the Athabasca River that are in use.

Sekani, Shuswap, Kootenay, Salish, Stoney, and Cree tribes hunted and fished along the river prior to European colonization in the 18th century. From about 1778, the Athabasca River, the Clearwater River, which enters the Athabasca River from the east at Fort McMurray, and the Methye Portage were part of a primary fur trade route from the Mackenzie River to the Great Lakes (see Canadian Canoe Routes (early)).

David Thompson and Thomas the Iroquois traveled through Athabasca Pass in 1811. In 1862, the Athabasca Springs area was crossed during the Cariboo Gold Rush by the Overlander Party.