| Blue Mill Stream | |
| Pushpin Map: | New York |
| Pushpin Map Caption: | Location of the mouth of Blue Mill Stream |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New York |
| Subdivision Type4: | County |
| Subdivision Name4: | Delaware |
| Source1 Coordinates: | 41.9056°N -75.2377°W |
| Mouth: | Delaware River |
| Mouth Coordinates: | 41.8804°N -75.2577°W[1] |
| Mouth Elevation: | 883feet |
Blue Mill Stream is a river in Delaware County, New York. It flows through Black Ash Swamp before converging with the Delaware River west-northwest Lordville.