| Official Name: | Mongaup Valley, New York |
| Settlement Type: | Hamlet and CDP |
| Pushpin Map: | New York#USA |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | New York |
| Subdivision Type2: | County |
| Subdivision Name2: | Sullivan |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 1112 |
| Coordinates: | 41.6686°N -74.7847°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 12762 |
| Area Code: | 845 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 957519 |
Mongaup Valley is a hamlet (and census-designated place)[1] in Sullivan County, New York, United States. The community is located along New York State Route 17B west of Monticello, and along the Mongaup River. Mongaup Valley has a post office with ZIP code 12762, which opened on June 22, 1848.[2] [3]