| Old Furnace, Delaware | |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | USA Delaware#USA |
| Pushpin Map Caption: | Location within the state of Delaware |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Delaware |
| Subdivision Type2: | County |
| Subdivision Name2: | Sussex |
| Unit Pref: | Imperial |
| Population As Of: | 2000 |
| Population Density Km2: | auto |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Coordinates: | 38.6669°N -75.5169°W |
| Postal Code Type: | ZIP codes |
| Blank Name: | FIPS code |
| Blank Info: | 54340 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 216167 |
Old Furnace is an unincorporated community located in Sussex County, Delaware, United States. The community is located in a rural area a few miles east of Seaford and approximately 40miles south of Dover. It is adjacent to the Old Furnace Wildlife Area.
The community is part of the Salisbury, Maryland-Delaware Metropolitan Statistical Area.