| Official Name: | Ontario, Indiana |
| Pushpin Map: | Indiana#USA |
| Pushpin Label: | Ontario |
| Pushpin Label Position: | bottom |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | LaGrange |
| Subdivision Type3: | Township |
| Subdivision Name3: | Lima |
| Coordinates: | 41.6986°N -85.3797°W |
| Elevation Ft: | 883 |
| Postal Code Type: | ZIP code |
| Postal Code: | 46746 |
| Blank Name: | FIPS code |
| Blank Info: | 18-56646[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2830437 |
Ontario is an unincorporated community in Lima Township, LaGrange County, Indiana.
Ontario was laid out in 1837.[2] The community took its name from Lake Ontario.[3] A post office opened at Ontario in 1846, and remained in operation until it was discontinued in 1943.[4]