Bute (; also known as the Isle of Bute) is an island in the Firth of Clyde in Scotland. It is divided into highland and lowland areas by the Highland Boundary Fault. Formerly part of the county of Buteshire, it now constitutes part of the council area of Argyll and Bute. Its resident population was 6,498 in 2011, a decline of just over 10% from the figure of 7,228 recorded in 2001 against a background of Scottish island populations as a whole growing by 4% to 103,702 for the same period.
The Isle of Bute has three parishes: Rothesay covering the town and some environs, Kingarth situated to the south of the island, and North Bute which covers the area north from the town limits of Rothesay and west to the hamlets facing the Kintyre Peninsula, as well as the subsidiary island of Inchmarnock. The sketchmap provided by GENUKI is a good illustration.
Bute is divided in two by the Highland Boundary Fault. North of the fault the island is hilly and largely uncultivated with extensive areas of forestry. The highest hill is Kames Hill at 267 metres. To the south of the fault the terrain is smoother and highly cultivated although in the far south is to be found the island's most rugged terrain around Glen Callum. Loch Fad is Bute's largest body of freshwater and runs along the fault line.
The western side of Bute is known for its beaches, many of which enjoy fine views over the Sound of Bute towards Arran and Bute's smaller satellite island Inchmarnock. Villages on the western side of the island include Straad, around St. Ninian's Bay, and Kildavanan on Ettrick Bay.
In the north, Bute is separated from the Cowal peninsula by the Kyles of Bute. The northern part of the island is sparsely populated, and the ferry terminal at Rhubodach connects the island to the mainland at Colintraive by the smaller of the island's two ferries. The crossing is one of the shortest, less than , and takes only a few minutes but is busy because many tourists prefer the scenic route to the island.
North Bute forms part of the Kyles of Bute National Scenic Area, one of 40 in Scotland.
Bute was absorbed into the Cenél Comgall of Dál Riata and colonised by Gaelic peoples. The island subsequently fell under Norse control and formed part of the Kingdom of the Isles, ruled by the Crovan dynasty. The Irish Text Martyrology of Tallaght makes a reference to Blane, the Bishop of Kingarth on Bute, "in Gall-Ghàidheil". However, in the 12th century, the island fell under the control of Somerled, Lord of Argyll, and possibly his Clann Somhairle descendants. At about the turn of the 13th century, Bute appears to have come into possession of the family of the Steward of Scotland, during a time of internal strife amongst Somerled's descendants.
In 1549, Dean Monro wrote of "Buitt" that it was:
very fertyle ground, namelie for aitts, with twa strenthes; the ane is the round castle of Buitt, callit Rosay of the auld, and Borrowstone about it callit Buitt. Before the town and castle is ane bay of sea, quhilk is a gude heavin for ships to ly upon ankers. That uther castle is callit the castle of Kames, quhilk Kames in Erishe is alsmeikle as to say in English the bay Castle. In this ile ther is twa paroche kirks, that ane southe callit the kirk of Bride, the uther northe in the Borrowstone of Buitt, with twa chappells, ane of them above the towne of Buitt, the uther under the forsaid castle of Kames.
In the 1940s and 1950s, Bute served as a large naval headquarters. During World War II it housed a large camp for officers and NCOs of the Polish Armed Forces in the West. Officially a military camp, it was unofficially thought of as a prison for Władysław Sikorski's political enemies.