Through the Middle Ages, when a dispute in Vendsyssel needed settling, it was settled here. The sysselting — the assembly for the whole syssel — met at Hjørring, which made this a town people travelled to rather than through, and the clergy gathered here as well. Three medieval churches survive to prove it, all within a few minutes' walk of one another. Sankt Olai is the oldest, possibly begun around 1038, Romanesque granite raised over a holy spring. Sankt Catharinæ is the largest, Romanesque brick that Gothic builders later stretched upward. Sankt Hans is the best preserved, and on its wall a fourteenth-century painter left a Saint Christopher, patron of travellers, wading a river with the Christ child on his shoulder. Three churches for one small town is not a measure of piety. It is a measure of traffic.

The name has never been satisfactorily explained. The leading guess joins hjórr, an Old Norse word for sword, to the -ing ending common in Danish place names, which would make Hjørring something like the sword place — perhaps describing a shape in the land, perhaps describing what once happened on it. The Latin form on the bracteate is the oldest written version anyone has found, and it settles nothing at all. A town can have nine centuries of documented history and still not know what it is called.

In 1819 fire took the south side of Østergade. Towns of timber and thatch burned regularly in nineteenth-century Denmark, and Hjørring's response was the usual one — rebuild, and rebuild outward — which pushed the town east along the street that has been its commercial spine ever since. The timing helped. A royal resolution of 4 September 1793 had made Hjørring the seat of the county administration, and when the amtmand's office finally opened on 1 January 1801 there were 744 people living here. Half a century later there were 1,914. The railway from Aalborg to Frederikshavn arrived on 15 August 1871, and the curve steepened: 6,055 residents by 1890, 7,901 by 1901.

Benedicte Wrensted was born here in 1859 and emigrated to the United States in 1894, where she built a career in Idaho as a photographer. Her best-known work is a body of portraits of Shoshone people — formal studio sittings in which the subjects sat as anyone else sat, composed and looking straight back at the lens. Ellen Osiier, born in Hjørring in 1890, travelled to the Paris Olympics of 1924 for the first women's fencing competition ever held at a Games and won all sixteen of her bouts; the gold was the first awarded to a woman in the sport. Johan Kjær Hansen did not leave. Born in 1907, he joined the Danish resistance during the German occupation and was executed by the occupying power in 1944, at thirty-seven.

Hjørring today has 25,794 residents (as of January 2026), which in most of Europe would make it a modest provincial town and in this corner of Denmark makes it the centre of everything. Vendsyssel is sparsely populated. The farms, the fishing harbours and the long summer-house coasts all need somewhere with a hospital, a court, a theatre and a proper shopping street, and Hjørring is that somewhere for the western and central parts of the region. The centre rewards wandering. Strømgade runs as a pedestrian street between Springvandspladsen, the fountain square, and Sct. Olai Plads; Østergade — the street that burned in 1819 — was pedestrianised in 2008 when the Metropol centre opened on it. The Vendsyssel Historiske Museum holds what the region has dug up, which after ten thousand years of occupation amounts to a great deal.