Coordinates: 55°58′N 4°32′W / 55.96°N 4.53°W / 55.96; -4.53

Dunbartonshire (Siorrachd Dhùn Bhreatainn in Gaelic) or the County of Dumbarton is a lieutenancy area and registration county in the west central Lowlands of Scotland lying to the north of the River Clyde. Until 1975 it was a county used as a primary unit of local government with its county town and administrative centre at the town of Dumbarton. The area had been previously been part of the historic district of Lennox, which was a duchy in the Peerage of Scotland related to the Duke of Lennox.

In modern local government, the county is divided into two of the thirty-two council areas of Scotland, namely East Dunbartonshire, with its administrative headquarters at Kirkintilloch, and West Dunbartonshire, with its administrative centre at Dumbarton.

Dumbarton was the county town from which the name of Dunbartonshire derives. The name of the town comes from the Scottish Gaelic Dùn Breatainn meaning "fort of the Britons".

Historically, the spelling of the county town and the county were not standardised. By the 18th century the names "County of Dunbarton" and "County of Dumbarton" were used interchangeably. Different county bodies used the two spellings: the Dunbarton County Constabulary were formed in 1857 by the Commissioners of Supply for the County of Dunbarton. Dumbartonshire County Council, set up under the Local Government (Scotland) Act 1889 adopted the spelling "Dunbartonshire" by 1914, a fact recognised by the Local Government (Scotland) Act 1947.

This article is about the East Dunbartonshire council area of Scotland. See also East Dunbartonshire (UK Parliament constituency).

East Dunbartonshire (Scots: Aest Dunbartonshire; Scottish Gaelic: Siorrachd Dhùn Bhreatainn an Ear) is one of the 32 council areas of Scotland. It borders onto the north-west of the City of Glasgow. It contains many of the suburbs of Glasgow as well as containing many of the city's commuter towns and villages. East Dunbartonshire also shares a border with West Dunbartonshire, Stirling, and North Lanarkshire. The council area covers part of the former county of Stirlingshire as well as parts of the former counties of Dunbartonshire and Lanarkshire.

The council area was formed in 1996, as a result of the Local Government etc. (Scotland) Act 1994, from part of the former Bearsden and Milngavie and Strathkelvin districts of the wider Strathclyde region.

East Dunbartonshire council area has low levels of deprivation, with relatively low unemployment and low levels of crime. The population is both declining and ageing.