In 1975 it became part of the Strathclyde Region, and was split up between districts. Bute and Inch Marnock were included in the district of Argyll & Bute, now a unitary authority, while Arran and the other islands, including the Cumbraes, which are nearer to Bute than Arran, became part of the district of Cunningham, which became the North Ayrshire unitary authority in 1996.
It is unique among the pre-1975 counties in that it disappeared altogether. The others remained in existence as ceremonial counties, with the Lord Lieutenant at their head. Some were modified in their area to take account of the new district boundaries. Two were combined, Perth & Kinross simply, Selkirkshire and Roxburghshire more complexly as Roxburgh, Ettrick and Lauder. The former Buteshire was divided ceremonially between the ceremonial counties of Argyll & Bute (Bute) and Ayrshire (Arran). It was thus less fortunate than Banffshire, another of the small counties, which had been divided between two new districts but retained its identity as a ceremonial county.