The County of Nairn was a general purpose county of Scotland, with the burgh of Nairn as the county town, until 1975, when, under the Local Government (Scotland) Act 1973, the county area became one of the eight districts of the two-tier Highland region. The county of Nairn survived for registration purposes and, at the same time, the Nairn lieutenancy was defined as having the boundaries of the new district. In 1996, under the Local Government etc (Scotland) Act 1994, the local government district was merged into the unitary Highland council area.
The county (Scottish Gaelic: Siorrachd Inbhir Narann), was described in 1846 as:
"about twenty-two miles in length and fifteen miles (35x24 km) in breadth; comprising an area of 200 square miles (520 km2), or 128,000 acres; 2338 houses, of which 2235 are inhabited; and containing a population of 9217."
Nairn can be seen from several distant points such as Ben Rinnes, a peak that is a common point of distant view to such places as the former county of Inverness and Longman Hill in the former county of Banff. To the north, Nairn is bounded by the Moray Firth.
Nairn (Scottish Gaelic: Inbhir Narann) is a land registration county.