| Harlan County Reservoir | |
|---|---|
 Outlet structure of Harlan County Dam, seen from downstream | |
  Harlan County Reservoir  Harlan County Reservoir | |
| Location | Harlan County, Nebraska / Phillips County, Kansas, United States |
| Coordinates | 40°04′15″N 099°12′41″W / 40.07083°N 99.21139°W |
| Type | reservoir |
| Primary inflows | Republican River |
| Primary outflows | Republican River |
| Basin countries | United States |
| Max. length | 9 mi (14 km) |
| Surface area | 13,250 acres (5,360 ha) |
| Surface elevation | 1,978 ft (603 m) |
| Settlements | Alma, Nebraska, Republican City, Nebraska |
The Harlan County Reservoir includes a dam and a reservoir of 13,250 acres (54 km2) located in Harlan County in south-central Nebraska. Its southernmost part extends into northern Phillips County, Kansas. The reservoir is formed by a dam constructed by the U.S. Army Corps of Engineers on the Republican River, which starts in Colorado and ends in Kansas.
The two closest towns are Republican City and Alma. Republican City offers fishing supplies, boat rentals, restaurants and cabins. When the lake is at normal pool, Alma is on the shore line of the lake and offers lodging, restaurants, stores, and churches.