Derry, New Hampshire - Wikipedia
FIPS code. 33-17940. GNIS feature ID. 0873578. Website. . Derry is a town in Rockingham County, New Hampshire, United States. The population was 34,317 at the 2020 census. [2] Although it is a town and not a city, Derry is the most populous community in Rockingham County and the fourth most populous in the state.