The first permanent European settlements in what is now New Hampshire occurred along the Piscataqua River in 1623, when two groups of families associated with the Fishmonger's Company of London located on Dover Neck and Little Harbor (now part of Portsmouth). It is highly probable that European fishermen had visited the Isles of Shoals and adjacent parts of the mainland for many years prior to 1623. Following these two settlements, towns sprang up in Exeter (1637) and Hampton (1638). For many years, New Hampshire consisted of these four communities. As their populations grew, the large tracts of land that comprised the four towns were subdivided until they included the many coastal communities seen today. The lands not claimed by the towns were covered by various patents granted to English entrepreneurs, whose heirs were still struggling over the titles decades later.

New Hampshire was a Royal Province until 1771 except for two short periods, 1642-79 and 1690-92, when it was under the control of Massachusetts. Because of New Hampshire's status as a Royal Province, it was in the peculiar position of separating the two parts of the Massachusetts Bay Colony, present-day Maine and Massachusetts.

People began migrating at a very early date from Middlesex and Essex counties, Massachusetts, into the seacoast area and the Merrimack River Valley, while settlers from New Hampshire and central and western Massachusetts were pushing their way up into what is now Cheshire County, with many settling as far inland as the interior parts of Grafton County.

A significant number of Ulster Scots settled in south central New Hampshire in 1718 and again in 1723. They had close familial ties with other Ulster Scots settlements in New England and Cherry Valley, then on the New York frontier, southwest of Albany. Originally settling in the old town of Londonderry, they spread out to found numerous other towns across the southern tier of New Hampshire.

Settlement of the interior of New Hampshire was effected largely by two waves of migrations. People from the seacoast were primarily responsible for settling the Lakes Region, the Upper Merrimack Valley, and "along the edge of Maine," whereas settlers from southern New England were primarily responsible for settling western and southwestern New Hampshire, with a mixture of both groups peopling the North Country. The settlers with seacoast origins had a further tendency to continue westward out of New Hampshire.

By the middle of the nineteenth century, French-Canadians began to move southward into New Hampshire to work in the mill towns and in the lumber industry. Migration from Quebec and later from the Maritime Provinces became very heavy between 1880 and 1920 and now accounts for over one-third of New Hampshire's population. Large numbers of Irish settlers came to the larger towns and cities following the potato famine and now comprise a significant portion of the population, while migrations of other ethnic groups to particular areas, often to work in specific trades, have added to the rich mosaic of New Hampshire's population. Such groups include the Poles of Franklin, the Greeks of Manchester and Laconia, as well as the Italians brought to New Hampshire to work as masons or road builders.