Jamestown is a borough in northwestern Mercer County, Pennsylvania, United States, along the Shenango River.

The Jamestown area is served by the Jamestown Area School District, and is home to Combined Systems, Inc., a tactical weapons producer that exports tear gas and smoke grenades.

[4] The Gibson House was added to the National Register of Historic Places in 1978.

There were 297 housing units at an average density of 382.7 per square mile (147.8/km2).

29.7% of all households were made up of individuals, and 15.6% had someone living alone who was 65 years of age or older.