| Gun Harbor Brook | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New York |
| Source1 Location: | Beaver River, New York |
| Source1 Coordinates: | 43.9425°N -74.9192°W |
| Mouth: | Stillwater Reservoir |
| Mouth Location: | Beaver River, New York |
| Mouth Coordinates: | 43.93°N -74.9258°W[1] |
| Mouth Elevation: | 1690feet |
Gun Harbor Brook is a river in Herkimer County, New York that flows into Stillwater Reservoir at Gun Harbor north of Beaver River, New York.