The term "Athabasca" is usually said to be a Cree word, although there is no evidence for this translation in Father Lacombe's Dictionnaire de la langue des Cris (1874). The river has not always been recorded as the Athabasca. In 1790, the lake was called "Lake of the Hills" and the river "Great Arabuska." In 1801 it was labelled "Athapasco" or "Elk River." The Arrowsmith map of 1802 shows a slight variation as "Arthapescow" or Elk River. In the late 18th century, the Beaver Indians who lived along its banks called it the Elk River, and it appears as the Elk on Alexander Mackenzie's map dated 1801. David Thompson and Peter Fidler, who explored the middle section of the river in 1799-1800, both referred to it in their journals as the Athabasca. It seems most likely that Mackenzie was using a translation of the Athapaskan word for the river while Thompson and Fidler were using the Cree name. One possibility for the origin of the name is that, since both the river and the large lake into which it drains were Beaver and Chipewyan territory in the 18th century, the name derives from the name of these Indian bands' common language, Athapaskan. Colonel Henry Inman, who journeyed down the Athabasca a year or two before the Klondike rush, claimed in Buffalo Jones' Forty Years of Adventure (1899) that the Indian word means "without a spirit" or, "God-forsaken." Other suggestions include a translation as "a chain of prairies like the meshes of a net" and "a low swampy piece of country with bare patches." The most readily accepted version of the name is that it is the Cree name meaning "where there are reeds," referring to the muddy delta of the river where it falls into Lake Athabasca. Local residents also refer to the river as simply "Big River."

Flows into Lake Athabasca, passing through Fort McMurray, Athabasca, etc.