| Rivière des Mornes | |
| Pushpin Map: | Quebec |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Quebec |
| Subdivision Type3: | Region |
| Subdivision Name3: | Chaudière-Appalaches |
| Subdivision Type4: | MRC |
| Subdivision Name4: | Bellechasse Regional County Municipality |
| Source1: | Mountain stream |
| Source1 Location: | Saint-Luc-de-Bellechasse |
| Mouth: | Rivière de la Fourche |
| Mouth Location: | Saint-Philémon |
| Progression: | Rivière de la Fourche, rivière du Sud (Montmagny), St. Lawrence River |
| Tributaries Left: | (upstream) |
| Tributaries Right: | (upstream) |
The rivière des Mornes (in English: Mornes river) crosses the municipality of Saint-Luc-de-Bellechasse (MRC Les Etchemins Regional County Municipality), as well as Notre-Dame-Auxiliatrice-de-Buckland and Saint-Philémon, in the Bellechasse Regional County Municipality, in the administrative region of Chaudière-Appalaches, in Québec, in Canada.
The Rivière des Mornes is a tributary of the west bank of the rivière de la Fourche, which flows northward to empty onto the south bank of the rivière du Sud (Montmagny); the latter flows northwest, then northeast to the south shore of the St. Lawrence River.
The main neighboring watersheds of the Des Mornes river are:
The Mornes river has its source in the township of Standon, in the municipality of Saint-Luc-de-Bellechasse, in the Les Etchemins Regional County Municipality. This source is located south of the summit of the "Montagne du Midi" of the "Massif du Sud". These mountains are part of the Notre Dame Mountains chain.
From its source, the Mornes river flows over, rolling down the mountain in a deep valley, divided into the following segments:
The confluence of the Mornes river is located at a place called "Les Trois-Fourches" and constitutes the head of the rivière de la Fourche. This confluence is located northeast of the summit of the Montagne du Midi, southeast of the hamlet of Buckland East and north-west of the summit of Mont Saint-Magloire.
The name “Rivière des Mornes” is associated with the mountainous terrain of the area.
The toponym “rivière des Mornes” was made official on February 18, 1977, at the Commission de toponymie du Québec.[2]