The County of Bute, also known as Buteshire, was one of the 34 traditional counties into which Scotland was divided for administrative purposes. It comprised the main islands of the Firth of Clyde, in particular the Isle of Bute, the Isle of Arran, Great Cumbrae and Little Cumbrae. The county town was Rothesay on Bute.
The County of Bute had Argyll to its west and Ayrshire to its east, though being made up of islands it had no land borders with other counties. A tidying up of the map of counties which reduced their number to 33 in 1890 had no effect on the County of Bute, 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 islands previously part of the County of Bute became part of the Strathclyde Region. The regions formed in 1975 were the upper tier of a two tier local authority system. Most regions were divided into a number of district council areas. The islands that had formed the County of Bute became part of Argyll District in the case of Bute itself, and Cunninghame District in the case of the other islands, including Arran.
Regions and districts disappeared from the scene in a major reorganisation in 1996, being replaced by 32 unitary council areas. Bute became part of the unitary council area of Argyll and Bute, while other islands previously part of the County of Bute became part of the unitary council area of North Ayrshire.