| Atimokateiw | |
| Map: | Gouin_Reservoir_74.72W_48.61.jpg |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Quebec |
| Subdivision Type3: | Region |
| Subdivision Name3: | Mauricie |
| Length: | 31.6km (19.6miles)[1] |
| Source1: | Unidentified Lake |
| Source1 Location: | La Tuque, Mauricie, Quebec |
| Source1 Coordinates: | 48.41°N -74.4056°W |
| Source1 Elevation: | 469m (1,539feet) |
| Mouth: | Gouin Reservoir (Kikendatch Bay) |
| Mouth Location: | La Tuque, Mauricie, Quebec |
| Mouth Coordinates: | 48.3736°N -74.3389°W |
| Mouth Elevation: | 402m (1,319feet) |
The Atimokateiw River is a tributary of the south shore of the Gouin Reservoir, flowing into the territory of the town of La Tuque, in the area of Mauricie, Quebec, Canada.
The Atimokateiw River flows entirely in the township of Aubin, to the south-east of the Gouin Reservoir. Forestry is the main economic activity of this valley; recreational tourism activities, second.
A forest road branch serves the valley of the Atimokateiw River and the peninsula which stretches north on . This road branch connects to route 400 which bypasses the south-eastern part of the Gouin Reservoir. It connects the village of Parent, Quebec (via the vallée of Bazin River) and the village Wemotaci, Quebec which is located west of La Tuque, Quebec.
The surface of the Atimokateiw River is usually frozen from mid-November to the end of April, however, safe ice circulation is generally from early December to late March.
This hydronym is of aboriginal origin.
The toponym "Atimokateiw River" was formalized on May 31, 1985 at the Commission de toponymie du Québec.[2]