Argyll, sometimes called Argyllshire, was one of the 34 traditional counties into which Scotland was divided for administrative purposes. It extended from Campbeltown and Kintyre in the south to Kinlochleven and Ardnamurchan in the north. It also included islands such as Mull and Islay. The county town was Inveraray.
Argyll was bordered by Inverness-shire, Perthshire, Dunbartonshire and the County of Bute. A tidying up of the map of counties which reduced their number to 33 in 1890 transferred control of the Small Isles from Argyll to Inverness-shire. It otherwise left Argyll unchanged, which as a result remained a county in its own right until reorganisation in 1975 swept all the counties away in favour of 12 regions.
The regions formed in 1975 were the upper tier of a two tier local authority system, and the area which had formed Argyll became part of the region of Strathclyde. Most regions were divided into a number of district council areas, and Strathclyde was divided into no fewer than 19 of them. These were grouped into six sub-regions, mostly based on the traditional counties which had become part of Strathclyde.
Argyll became a district council area and a sub-region of Strathclyde in its own right. There were two main boundary changes during the transition from a county to a district in 1975. On the one hand, an area to the north of the county, including Ardnamurchan, Kinlochleven and Ballachulish, was lost to the Lochaber District of Highland Region. On the other, the Isle of Bute, formerly part of the separate County of Bute, became part of Argyll.
Regions and districts disappeared from the scene in a major reorganisation in 1996, being replaced by 32 unitary council areas. Argyll District became the unitary council area of Argyll and Bute.