Isurium or Isurium of the Brigantes was a Roman fort and town in the province of Britannia at the site of present-day Aldborough in North Yorkshire, England, in the United Kingdom. Its remains—the Aldborough Roman Site—are in the care of English Heritage.
The Roman road through the town formed a leg of both Dere Street—connecting Eboracum (York) to the Antonine Wall—and the Roman equivalent of Watling Street, which here connected Eboracum with Luguvalium (Carlisle). The modern village retains part of the Roman street plan and the church stands on the site of the forum.