is a town in Hillsborough County, New Hampshire, United States. The population was 5,883 at the 2000 census, with an estimated population of 6,100 in 2006.
The town center, where over 50% of the population resides, is defined as the Peterborough census-designated place (CDP), and is located near the intersection of U.S. Route 202 and New Hampshire Route 101 along the Contoocook River.
According to the United States Census Bureau, the town has a total area of , of which is land and is water, comprising 1.08% of the town. The highest point in Peterborough is South Pack Monadnock Mountain ( above sea level), in Miller State Park.
The town center, or census-designated place, has a total area of , of which is land and (0.42%) is water.