| Official Name: | Fiat, Indiana |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | Indiana#USA |
| Pushpin Label: | Fiat |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Jay |
| Subdivision Type3: | Township |
| Subdivision Name3: | Penn Township |
| Coordinates: | 40.5533°N -85.15°W |
| Elevation Ft: | 902 |
| Postal Code Type: | ZIP code |
| Blank Name: | FIPS code |
| Blank Info: | 18-23116[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 434469 |
Fiat is an unincorporated community in Penn Township, Jay County, Indiana.
A post office was established at Fiat in 1881, and remained in operation until it was discontinued in 1926.[2] The political issue of United States Notes (fiat money) likely caused the community's name to be selected.[3]
Located approximately east of Fiat is a round barn.[4] Known as the Rebecca Rankin Round Barn, it was built in 1908, and it is listed on the National Register of Historic Places.