Princeton is a town in Worcester County, Massachusetts, United States. It is bordered on the east by Sterling and Leominster, on the north by Westminster, on the northwest by Hubbardston, on the southwest by Rutland, and on the southeast by Holden. The preeminent landmark within Princeton is Mount Wachusett, which straddles the line between Princeton and Westminster but the entrance to which is within Princeton. According to tradition, in 1675, Mary Rowlandson was ransomed upon Redemption Rock, now within the town of Princeton, by King Philip. The population was 3,495 at the 2020 census. Princeton is a rural exurb, serving as a bedroom commuter town for nearby cities such as Worcester, Gardner, and Boston.

Worcester County is a county in the U.S. state of Massachusetts. At the 2020 census, the population was 862,111, making it the second-most populous county in Massachusetts. It is also the largest county in Massachusetts by geographic area. The largest city and traditional shire town is Worcester. Worcester County is part of the Worcester, MA–CT metropolitan statistical area and the Boston-Worcester-Providence combined statistical area.