| Official Name: | Blue, Indiana |
| Settlement Type: | Unincorporated Community |
| Pushpin Map: | Indiana#USA |
| Pushpin Label: | Blue |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Ohio |
| Subdivision Type3: | Township |
| Subdivision Name3: | Cass |
| Elevation Ft: | 873 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -6 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -5 |
| Coordinates: | 38.925°N -85.0047°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 47040 |
| Area Codes: | 812, 930 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 431213 |
Blue is an unincorporated community in Cass Township, Ohio County, in the U.S. state of Indiana.
A post office was established at Blue in 1890, and remained in operation until it was discontinued in 1907.[1]