Nashua is a city in southern New Hampshire, United States. At the 2020 census, it had a population of 91,322, the second-largest in northern New England after nearby Manchester. Along with Manchester, it is a seat of New Hampshire’s most populous county, Hillsborough.

Built around the now-departed textile industry, in recent decades Nashua’s economy has shifted to the financial services, high tech, and defense industries as part of the economic recovery that started in the 1980s in the Greater Boston region. Major private employers in the city include Nashua Corporation, BAE Systems, and Teradyne. The city also hosts two major regional medical centers, Southern New Hampshire Medical Center and St. Joseph Hospital. The South Nashua commercial district is a major regional shopping destination, lying directly on the Massachusetts border and taking advantage of New Hampshire’s lack of sales tax. It is anchored by the Pheasant Lane Mall and numerous smaller shopping centers.

Nashua was three times named one of the “Best Places to Live in America” in annual surveys by Money magazine, most recently in 2022. It is one of many cities nicknamed “Gate City” because they are seen as the entry point, or gateway, to a region.

The area was part of a 200-square-mile (520 km) tract of land in Massachusetts called “Dunstable”, named after Edward Tyng of Dunstable in England. Located at the confluence of the Nashua and Merrimack rivers, Dunstable was first settled about 1654 as a fur trading town. Nashua lies approximately in the center of the original 1673 grant. In 1732, Dunstable was split along the Merrimack River, with the town of Nottingham West (now the town of Hudson, New Hampshire) created out of the eastern portion. The previously disputed boundary between Massachusetts and New Hampshire was fixed in 1741 when the governorships of the two provinces were separated. As a result, the township of Dunstable was divided in two. Tyngsborough and some of Dunstable remained in Massachusetts, while Dunstable, New Hampshire, was incorporated in 1746 from the northern section of the town.

Like many 19th century riverfront New England communities, New Hampshire’s Dunstable was developed during the Industrial Revolution with textile mills operated from water power. In 1823, the Nashua Manufacturing Company was incorporated. The company eventually had four mills and employed approximately 1,000 people. The following year, the Jackson Manufacturing Company was incorporated.

In 1836, the New Hampshire half of Dunstable was renamed “Nashua”, after the Nashua River; the Dunstable name lives on across the Massachusetts border. The Nashua River was named by the Nashaway people, and in the Penacook language it means “beautiful stream with a pebbly bottom”, with an alternative meaning of “land between two rivers”. In 1842, the town split into two towns. Eleven years later, they joined back together under the name “Nashua”, and were re-incorporated as a city. During the split, the northern area, known today as “French Hill”, called itself “Nashville”, while the southern part kept the name Nashua.