| Official Name: | Duff, Indiana |
| Pushpin Map: | Indiana#USA |
| Pushpin Label: | Duff |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Dubois |
| Subdivision Type3: | Township |
| Subdivision Name3: | Patoka |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Coordinates: | 38.3272°N -87.0264°W |
| Elevation Ft: | 466 |
| Postal Code Type: | ZIP code |
| Postal Code: | 47542 |
| Area Code: | 812, 930 |
| Blank Name: | FIPS code |
| Blank Info: | 18-18874[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 433754 |
Duff is an unincorporated community in Patoka Township, Dubois County, in the U.S. state of Indiana.
Duff was platted in 1883 by Robert Small. It was likely named for Col. B. B. Edmonston, who had the nickname "Colonel Duff".[2]
A post office was established at Duff in 1868, and remained in operation until it was discontinued in 1955.[3]