Londonderry is a town in western Rockingham County, New Hampshire, United States. The town is bordered on the north by the city of Manchester and on the east by the town of Derry. The population was 24,129 at the 2010 census. Londonderry is known for its apple orchards and is home to the headquarters of Stonyfield Farm and partial home to Manchester-Boston Regional Airport.The more densely settled portion of town, where 11,037 people resided at the 2010 census, is defined as the Londonderry census-designated place and roughly occupies the southeastern and southern parts of town, around New Hampshire Route 102.