| Official Name: | Greenwich, Massachusetts |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Massachusetts |
| Subdivision Type2: | County |
| Subdivision Name2: | Hampshire |
| Established Title2: | Incorporated |
| Established Date2: | 1739 |
| Established Title3: | Disincorporated |
| Established Date3: | April 28, 1938 |
| Population As Of: | 0 |
| Settlement Type: | Town |
| Timezone: | Eastern |
| Utc Offset: | -5 |
| Timezone Dst: | Eastern |
| Coordinates: | 42.3592°N -72.2964°W |
| Blank1 Name: | GNIS feature ID |
Greenwich [1] was a town in Hampshire County, Massachusetts, United States. The town was lost as a result of the formation of the Quabbin Reservoir in order to supply Boston's growing water needs.
Greenwich was established in 1739 as Quabbin, incorporated as Quabbin Parish in 1754, and became the town of Greenwich (named for John Campbell, Duke of Greenwich) in 1754. It was located along the East and Middle branches of the Swift River. The Athol Branch of the Boston and Albany Railroad ran through the center of town, as did Route 21. It was well known for its lakes and ponds, which were popular vacation spots. It bordered four towns—Enfield, Prescott, Dana, and Hardwick.
H. P. Lovecraft's fictional town of Dunwich in his seminal story "The Dunwich Horror" was partially based on the town of Greenwich.[2] Additionally, Lovecraft's story "The Colour Out of Space" is set in this valley before it was flooded for the reservoir.[3]
Greenwich was disincorporated on April 28, 1938, as part of the creation of the Quabbin Reservoir. Upon disincorporation, portions of the town were annexed to the adjacent towns of Hardwick, New Salem, Petersham, and Ware. (Because of the redrawing of town lines, the land is no longer completely in Hampshire County; only the portion located in Ware is.) Because most of Greenwich was at lower elevation than the surrounding towns, it is now largely submerged, except for the hilltops of Curtis Hill, Mount Lizzie and Mount Pomeroy, which are now islands.