The river is named after Simon Fraser [1776–1862], who led an expedition in 1808 on behalf of the North West Company from the site of present-day Prince George almost to the mouth of the river. The river’s name in the Carrier (Dakelh) language is Lhtakoh. The Tsilhqot’in name for the river, not dissimilar to the Dakelh name, is ʔElhdaqox, meaning Sturgeon (ʔElhda-chugh) River (Yeqox).

The name was officially adopted by the Geographic Board of Canada in 1910, as long-identified on maps and in journals. The name was re-approved in in 1915 to specifically identify the Fraser River as the main channel sometimes known as the South Fork Fraser River (the portion between Yellowhead Lake and Prince George), the former North Fork Fraser River being the current McGregor River.

The first European to mention the Fraser River was Alexander Mackenzie [1764–1820] during his journey to the Pacific in 1793. On a map printed with his Voyages in 1801, Mackenzie called the river “Tacoutche Tesse, or Columbia River.” The Spanish explorers never found their way up the mouth of the Fraser, but in 1791, finding evidence that they were near the mouth of a major river, they named it “Rio Floridablanca” in honor of the prime minister of Spain.

The Fraser River was also known in the early days as the New Caledonia River. It was named after Simon Fraser in 1813 by David Thompson [1770–1857] (the Thompson River was given its name by Fraser).

“Fraser River / Fleuve Fraser” is among the 75 “Pan-Canadian names,” large and well-known Canadian features and areas designated in Treasury Board Circular 1983-58 to require presentation in both official languages of Canada on federal maps. In French, a fleuve is a river that flows into an ocean or sea.