| Official Name: | Grantsburg, Illinois |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | Illinois#USA |
| Pushpin Label: | Grantsburg |
| Pushpin Label Position: | top |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Johnson |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 367 |
| Coordinates: | 37.3908°N -88.7469°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 62943 |
| Area Code: | 618 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 409314 |
Grantsburg is an unincorporated community in Johnson County, Illinois, United States. Grantsburg is located on Illinois Route 146 near the Shawnee National Forest, east of Vienna. Grantsburg has a post office, with the ZIP code 62943.[1]