Post Offices List in Grant County, Indiana:
| Fairmount Post Office | 204 S Main St, Fairmount, IN 46928 |
| Gas City Post Office | 123 N 2nd St, Gas City, IN 46933 |
| Marion Post Office | 202 W 3rd St, Marion, IN 46952 |
| Matthews Post Office | 702 Massachusetts Ave, Matthews, IN 46957 |
| Swayzee Post Office | 111 N Washington St, Swayzee, IN 46986 |
| Sweetser Post Office | 111 W Greenburg St, Sweetser, IN 46987 |
| Upland Post Office | 222 N Main St, Upland, IN 46989 |
| Van Buren Post Office | 113 E Main St, Van Buren, IN 46991 |