| Post Office Name | US Post Office |
| Address | 111 E Main St |
| City | Castlewood |
| State | South Dakota |
| Phone Number | (605) 793-2658 |
| Latitude | 44.7326 |
| Longitude | -97.0258 |
57223 US Post Office in Castlewood, South Dakota is located at 111 E Main St. The Castlewood Post Office Number is (605) 793-2658