| Official Name: | Boundary, Washington |
| Pushpin Map: | Washington#USA |
| Pushpin Label: | Boundary |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Washington |
| Subdivision Type2: | County |
| Subdivision Name2: | Stevens |
| Population As Of: | 1890s |
| Population Total: | approx. 900 |
| Timezone: | Pacific (PST) |
| Utc Offset: | -8 |
| Timezone Dst: | PDT |
| Utc Offset Dst: | -7 |
| Postal Code Type: | ZIP code |
| Blank Name: | FIPS code |
| Blank1 Name: | GNIS feature ID |
Boundary is a ghost town located in Stevens County, Washington, United States. The town was located near the Canada–US border and near the Columbia River. Boundary's peak years were during the 1890s. The population was around 900. The town started off as a railroad camp. When the railroad finally spanned the wild Pend Oreille with a bridge, the railroad workers quickly moved on leaving the town of Boundary deserted. The town contained the Boundary Hotel, post office, and general store. A town called "New Boundary" came into being south of the original townsite and the old town eventually vanished.