The Chaudière River (French for "Cauldron" or "Boiler"; Abenaki: Kik8ntekw^[1][2]) is a 185-kilometre-long (115 mi) river with its source near the Town of Lac-Mégantic, in southeast Quebec, Canada. From its source Lake Mégantic in the Estrie region, it runs northwards to flow into the St. Lawrence River opposite Quebec City.

The river's drainage area is 6,682 square kilometres (2,580 sq mi), initially in the Appalachian Mountains, then in the low-lands of the St. Lawrence, and include 236 lakes covering 62 square kilometres (24 sq mi) and approximately 180,000 inhabitants. Its annual medium flow at the station of Saint-Lambert-de-Lauzon is 114 cubic metres per second (4,000 cu ft/s), varying from 11 cubic metres per second (390 cu ft/s) (low water) to 470 cubic metres per second (17,000 cu ft/s) (spring high water), with historical maximum of 1,760 cubic metres per second (62,000 cu ft/s).

Its principal tributaries are:

• Rivière du Loup (not to be confused with Rivière du Loup in the Bas-Saint-Laurent), also known as the Rivière Linière
• Famine River
• Beaurivage River
• Bras Saint-Victor

The river's basin has nearly 50 percent of the faunal richness of Quebec, namely 330 out of 653 vertebrate species known in the province can be found there.

The river, and the 40-metre-high (130 ft) Chaudière Falls which it passes over, are popular outdoor recreation areas.

The Abenaki Nation, whose homeland Ndakinna encompasses the river and Chaudière Falls, call it "Kik8ntekw" or "Kikonteku", meaning "River of the Fields." On the charts of Samuel de Champlain, it was given the name "Etchemin River" (a name now used for another river whose drainage area borders with that of the Chaudière River). It was called "Rivière du Sault de la Chaudière" for a period of time before it became simply "Rivière Chaudière" towards the end of the 18th century. This name translates as boiler and refers to the waterfall close to its mouth.

Its location was strategic for French colonization during the 18th century, because the river was a natural link between New France and the British colonies to the south. It was also used by Benedict Arnold at the time of his 1775 expedition in the invasion of Quebec.

In 1823, gold was found along its shores in the Eastern Townships of Quebec.^[3]

On 6 July 2013 the Lac-Mégantic derailment caused a major oil spill which contaminated the river at its source at Lac Mégantic.^[4] Downstream communities such as Saint-Georges (80 kilometres (50 mi) to the northeast) were forced to obtain potable water from alternate sources and residents asked to limit their water consumption.^[5] Floating barriers were installed in an attempt to contain the contamination.

The Chaudière Valley largely crosses the Quebec region of Beauce. It has shaped its industries and its way of life, particularly in spring when its overflows during snowmelt in inhabited areas are frequent, despite its course regulated by 160 dams and retaining dikes. The river runs through several towns and villages in the region, including Saint-Ludger, Saint-Gédéon-de-Beauce, Saint-Martin, Saint-Georges, Notre-Dame-des-Pins, Beauceville, Saint-Joseph-de-Beauce, Vallée-Jonction and Sainte-Marie, Quebec.

The river is a prime site for outdoor activities, particularly near lac Mégantic and Chutes-de-la-Chaudière park. Located near the mouth of the river, in Lévis, this park offers hiking and cycling trails as well as a footbridge suspended over the river, which offers a viewpoint on the fall, 35 metres (115 ft) high. The fall was harnessed for its hydro-electric potential in 1901, but was destroyed in 1970. The dam was rebuilt in 1999 on the remains of the old installations, and supplies a small hydro-electric plant of 24 megawatts (32,000 hp). ^[6]

• List of rivers of Quebec