| Official Name: | Lost River, Indiana |
| Pushpin Map: | Indiana#USA |
| Pushpin Label: | Lost River |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Orange |
| Subdivision Type3: | Township |
| Subdivision Name3: | Paoli |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Coordinates: | 38.6069°N -86.4514°W |
| Elevation Ft: | 637 |
| Postal Code Type: | ZIP code |
| Postal Code: | 47454 |
| Area Code: | 812, 930 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 451660 |
Lost River is an unincorporated community in Paoli Township, Orange County, in the U.S. state of Indiana.
A post office was established at Lost River in 1837, and remained in operation until 1878.[1] The community took its name from the nearby Lost River.[2]