Among the longest rivers of Canada are 47 streams of at least . In the case of some rivers such as the Columbia, the length listed in the table below is solely that of the main stem. In the case of others such as the Mackenzie, it is the combined lengths of the main stem and one or more upstream tributaries, as noted. Excluded from the list are rivers such as the Dauphin, a short connecting link between lakes Manitoba and Winnipeg, with main stems of or less. Also excluded are rivers such as the Mississippi, the main stems of which do not enter Canada even though some of their tributaries do.

Nine rivers in this list cross international boundaries or form them. Four—the Yukon, Columbia, Porcupine, and Kootenay—begin in Canada and flow into the United States. Five—the Milk, Pend d'Oreille, Saint Lawrence, Red, and Saint John—begin in the United States and flow into Canada. Of these, the Milk and the Kootenay cross the international border twice, the Milk leaving and then re-entering the United States, the Kootenay leaving and then re-entering Canada. The drainage basins of these nine rivers extend into both countries; in addition, the drainage basins of six others—the Fraser, Assiniboine, South Saskatchewan, Saskatchewan, Nelson, and Winnipeg—extend into the United States even though their main stems flow entirely within Canada.

Sources report hydrological quantities with varied precision. Biologist and author Ruth Patrick, describing a table of high-discharge rivers, wrote that data on discharge, drainage area, and length varied widely among authors whose works she consulted. "It seems", she said, "that the wisest course is to regard data tables such as the present one as showing the general ranks of rivers, and not to place too much importance on minor (10–20%) differences in figures."

Table The primary source for data in the table below is The Atlas of Canada; other sources are as noted. Discharge refers to the flow at the mouth except as noted. U.S. states appear in italics. Abbreviations are as follows: "km" for "kilometre", "mi" for "mile", "s" for "second", "m" for "metre", and "ft" for "foot".

Key River is not entirely within Canada. Watershed is not entirely within Canada.

+ Longest rivers of Canada#NameMouthLengthSourceWatershedareaFrom The Atlas of Canada unless otherwise notedDischargeMeasured at the mouth unless otherwise notedProvinces, statesImage1Mackenzie RiverBeaufort Sea km2,635 miThutade Lake km2697,000 mi2  m3/s340,000 ft3/sNorthwest Territories 2Yukon RiverBering Sea km1,979 miTeslin Lake km2324,000 mi2  m3/s224,000 ft3/sBenke and Cushing, p. 796British Columbia, Yukon, Alaska 3Saint Lawrence RiverGulf of Saint Lawrence  km1,900 miSeven Beaver Lake  km2519,000 mi2  m3/s348,000 ft3/sMinnesota, Wisconsin, Ontario, Michigan, Ohio, New York, Quebec4Nelson RiverHudson Bay  km1,600 miBow Glacier km2344,500 mi2 m3/s84,000 ft3/sManitoba 5Slave RiverGreat Slave Lake  km1,453 miThutade Lake  km2238,000 mi2 m3/s121,400 ft3/sBenke and Cushing, p. 843Alberta, Northwest Territories 6Columbia RiverPacific Ocean km1,243 mi Columbia Lake km2259,200 mi2  m3/s273,000 ft3/sBenke and Cushing, p. 646 British Columbia, Washington, Oregon7Saskatchewan RiverLake Winnipeg  km1,205 miBow Glacier km2129,700 mi2  m3/s25,000 ft3/s Alberta, Saskatchewan, Manitoba 8Peace RiverSlave River km1,195 mi Thutade Lake  km2116,800 mi2 m3/s74,800 ft3/sBenke and Cushing, p. 844British Columbia, Alberta9Churchill River (Hudson Bay)Hudson Bay km1,000 miChurchill Lake km2108,600 mi2 m3/s42,000 ft3/sAlberta, Saskatchewan, Manitoba10South Saskatchewan RiverSaskatchewan River km865 miBow Glacier  km256,400 mi2  m3/s9,900  ft3/s Alberta, Saskatchewan11Fraser RiverStrait of Georgia km854 miFraser Pass km290,000 mi2  m3/s125,000 ft3/s British Columbia12North Saskatchewan RiverSaskatchewan River  km800 miSaskatchewan Glacier km247,400 mi2  m3/s8,700 ft3/s Alberta, Saskatchewan13Ottawa RiverSaint Lawrence River  km790 miLaurentian Mountains  km256,500 mi2 m3/s69,000 ft3/s Quebec, Ontario14Athabasca RiverLake Athabasca km765 mi Columbia Icefield km236,800 mi2  m3/s27,700 ft3/sBenke and Cushing, p. 845 Alberta15Liard RiverMackenzie River  km693 miBenke and Cushing, p. 815 Saint Cyr Range km2107,000 mi2  m3/s86,400 ft3/sBenke and Cushing, p. 842Yukon, British Columbia, Northwest Territories16Assiniboine RiverRed River km660 minear Hazel Dell  km270,000 mi2  m3/s1,600 ft3/sSaskatchewan, Manitoba17Milk RiverMissouri River  km625 miBlackfeet Indian Reservation km223,600 mi2 m3/s670 ft3/sBenke and Cushing, p. 475Alberta, Montana18Albany RiverJames Bay  km610 miCat Lake  km252,200 mi2  m3/s8,900 ft3/s Ontario19Severn River Hudson Bay  km610 miDeer Lake km239,700 mi2  m3/s22,800 ft3/s Ontario20Back RiverChantrey Inlet  km605 minear Aylmer Lake  km241,120 mi2  m3/s21,600 ft3/s Northwest Territories, Nunavut21Thelon RiverBaker Lake  km562 miLynx Lake  km255,000 mi2 m3/s30,000 ft3/sNorthwest Territories, Nunavut22La Grande RiverJames Bay  km555 mi Lac Nichicun km237,700 mi2  m3/s60,000 ft3/sQuebec23Red RiverLake Winnipeg km545 miWahpeton and Breckinridge km2111,000 mi2 m3/s8,300 ft3/sBenke and Cushing, p. 896North Dakota, Minnesota, Manitoba 24Koksoak RiverUngava Bay km543 miLake Sevestre  km251,500 mi2 m3/s99,000 ft3/s Quebec 25Churchill River (Atlantic)Lake Melville km532 miAshuanipi Lake  km230,800 mi2 m3/s56,000 ft3/s Newfoundland and Labrador26Coppermine RiverCoronation Gulf km525 miLac de Gras km219,600 mi2 m3/s9,300 ft3/sNorthwest Territories, Nunavut27Dubawnt RiverThelon River  km523 mi Abitau Lake km222,200 mi2  m3/s12,900 ft3/s Northwest Territories, Nunavut 28Winnipeg RiverLake Winnipeg km505 miTrap Lake km252,400 mi2  m3/s30,000 ft3/sBenke and Cushing, p. 898Ontario, Manitoba 29Kootenay RiverColumbia River km485 miBeaverfoot Range  km219,400 mi2  m3/s30,000 ft3/sBritish Columbia, Montana, Idaho30Nottaway River James Bay km482 mi Lake Gilles  km225,400 mi2  m3/s42000 ft3/s Quebec31Rupert River James Bay  km474 minorth of Lake Mistassini  km216,800 mi2 m3/s32,000 ft3/s Quebec 32Eastmain RiverJames Bay  km470 miLac Bréhat  km217,900 mi2  m3/s33,000 ft3/s Quebec 33Attawapiskat River James Bay  km465 miAttawapiskat Lake km219,500 mi2  m3/s9,300 ft3/s Ontario34Kazan River Thelon River km455 miEnnadai Lake km227,600 mi2 m3/s19,000 ft3/s Nunavut 35Red Deer RiverSouth Saskatchewan River km450 miSawback Range  km217,400 mi2  m3/s2,500 ft3/sAlberta 36Great Whale River Hudson Bay  km450 miLake Saint-Lusson  km216,500 mi2  m3/s24,000 ft3/sQuebec 37Porcupine RiverYukon River km448 miOgilvie Mountains km245,500 mi2  m3/s14,600 ft3/sBenke and Cushing, p. 802 Yukon, Alaska 38Pend d'Oreille RiverColumbia River km437 minear Butte  km225,800 mi2  m3/s29,000 ft3/s Idaho, Washington, British Columbia 39Hay RiverGreat Slave Lake  km436 minear Zama Lake  km218,600 mi2 m3/s4,000 ft3/sBenke and Cushing, p. 848 Alberta, Northwest Territories 40Saguenay RiverSaint Lawrence River  km434 minear Otish Mountains  km234,000 mi2  m3/s62,000 ft3/s Quebec 41Anderson RiverBeaufort Sea km430 minorthwest of Great Bear Lake  m3/s5,000 ft3/sNorthwest Territories 42Peel RiverMackenzie River  km425 miGill Lake km228,400 mi2 m3/s3,600 ft3/sBenke and Cushing, p. 850 Yukon, Northwest Territories 43Saint John RiverBay of Fundy km418 miSomerset County  km221,300 mi2 m3/s40,000 ft3/s Maine, New Brunswick 44Stewart RiverYukon River  km400 miSelwyn Mountains  km220,000 mi2  m3/s23,800 ft3/sBenke and Cushing, p. 800 Yukon45Horton RiverFranklin Bay km384 miKitikmeot Region, Nunavut  km210,300 mi2 Nunavut, Northwest Territories 46English RiverWinnipeg River km382 minear Marmion Lake  km220,200 mi2 Ontario 47Pelly RiverYukon River km378 miMackenzie Mountains km220,000 mi2 m3/s14,000 ft3/s Yukon

See also List of rivers of Canada

Notes and references Notes

References

Works cited Benke, Arthur C., ed., and Cushing, Colbert E., ed. Rivers of North America. Burlington, Massachusetts: Elsevier Academic Press.