| Cooney Reservoir | |
| Pushpin Map: | USA Montana |
| Coords: | 45.4439°N -109.2219°W |
| Lake Type: | Reservoir |
| Inflow: | Red Lodge Creek, Willow Creek, Chapman Creek |
| Outflow: | Red Lodge Creek |
| Basin Countries: | United States |
| Location: | Carbon County, Montana |
| Elevation: | 4222feet |
Cooney Dam is a dam in Carbon County, Montana, that creates Cooney Reservoir.
The earthen dam was constructed in 1937 by the State of Montana, with a height of, and a length of at its crest. It impounds Red Lodge Creek for irrigation water storage. The dam is owned and operated by the Montana Department of Natural Resources and Conservation.
The reservoir it creates, Cooney Reservoir, has a normal water surface of, a maximum storage capacity of, and a normal capacity of . Recreation includes boating, camping, hiking, and fishing for walleye and rainbow trout. The state maintains the adjacent Cooney State Park.