The existing constituency was created as a result of the Fifth Periodical Review of the Boundary Commission for Scotland, as one of two covering the East Dunbartonshire council area and one of five covering the East Dunbartonshire council area and the North Lanarkshire council area.

The East Dunbartonshire constituency is entirely within the East Dunbartonshire council area, and the rest of the council area is covered by the Cumbernauld, Kilsyth and Kirkintilloch East constituency, which also covers part of the North Lanarkshire council area. The rest of the North Lanarkshire area is covered by the Airdrie and Shotts, Coatbridge, Chryston and Bellshill, and Motherwell and Wishaw constituencies.

The East Dunbartonshire constituency replaced most of the Strathkelvin and Bearsden constituency and some of the Clydebank and Milngavie constituency and some of the Coatbridge and Chryston constituency.

The Fifth Periodical Review did not affect the boundaries of Scottish Parliament constituencies, which retain the boundaries of Westminster constituencies prior to implementation of the results of the review.

The historic constituency was created under the House of Commons (Redistribution of Seats) Act 1949, and first used in the 1950 general election.

As created in 1950, the constituency was one of two covering the county of Dunbarton. The other was West Dunbartonshire. The two new constituencies replaced the earlier constituencies of Dunbartonshire and Dumbarton Burghs.

East Dunbartonshire covered the Cumbernauld, Kirkintilloch, and New Kilpatrick districts of the county and the burghs of Clydebank, Kirkintilloch, and Milngavie.

For the 1951 general election the constituency boundaries were adjusted to take account of a change to the boundaries of the burgh of Clydebank.

The results of the First Periodical Review of the Boundary Commission were implemented for the 1955 general election, but there was no change to the boundaries of East Dunbartonshire, and the boundaries of 1951 and 1955 were used also in the general elections of 1959, 1964, 1966 and 1970.

The results of the Second Periodical Review were implemented for the February 1974 general election. The review took account of population growth in the county of Dunbarton, caused by overspill from the city of Glasgow into the new town of Cumbernauld and elsewhere, and East Dunbartonshire became one of three constituencies covering the county. East Dunbartonshire now covered the Kirkintilloch and Cumbernauld districts of the county and the burghs of Bearsden, Cumbernauld, and Kirkintilloch, but it lost Clydebank and Milngavie to the new constituency of Central Dunbartonshire. These boundaries were used also for the general elections of October 1974 and 1979.

In 1975, under the Local Government (Scotland) Act 1973, Scottish counties were abolished in favour of regions and districts and islands council areas, and the county of Dunbarton was divided between several districts of the new region of Strathclyde. The Third Periodical Review took account of new local government boundaries, and the results were implemented for the 1983 general election.

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  East Dunbartonshire election history

General election 2019: East Dunbartonshire

Party		Candidate	Votes	%	±%
	SNP	Amy Callaghan	19,672	37.1	6.8
	Liberal Democrats	Jo Swinson	19,523	36.8	3.8
	Conservative	Pam Gosal	7,455	14.1	0.5
	Labour	Callum McNally	4,839	9.1	5.4
	Scottish Green	Carolynn Scrimgeour	916	1.7	New
	Independent	Rosie Dickson	221	0.4	New
	UKIP	Donald MacKay	208	0.4	New
	Scottish Family	Liam McKechnie	197	0.4	New
Majority			149	0.3	N/A
Turnout			53,031	80.3	1.5
	SNP gain from Liberal Democrats		Swing	5.3

This was the largest constituency turnout, and the smallest SNP majority, at the 2019 general election.

General election 2017: East Dunbartonshire

Party		Candidate	Votes	%	±%
	Liberal Democrats	Jo Swinson	21,023	40.6	4.3
	SNP	John Nicolson	15,684	30.3	10.0
	Conservative	Sheila Mechan	7,563	14.6	6.0
	Labour	Callum McNally	7,531	14.5	2.2
Majority			5,339	10.3	N/A
Turnout			51,801	78.8	3.1
	Liberal Democrats gain from SNP		Swing	7.2

General election 2015: East Dunbartonshire

Party		Candidate	Votes	%	±%
	SNP	John Nicolson	22,093	40.3	29.8
	Liberal Democrats	Jo Swinson	19,926	36.3	2.4
	Labour	Amanjit Jhund	6,754	12.3	21.8
	Conservative	Andrew Polson	4,727	8.6	6.9
	Scottish Green	Ross Greer	804	1.5	New
	UKIP	Wilfred Arasaratnam	567	1.0	0.1
Majority			2,167	4.0	N/A
Turnout			54,871	81.9	6.7
	SNP gain from Liberal Democrats		Swing	16.0

This was the highest turnout in the May 2015 general election.

General election 2010: East Dunbartonshire

Party		Candidate	Votes	%	±%
	Liberal Democrats	Jo Swinson	18,551	38.7	3.1
	Labour	Mary Galbraith	16,367	34.1	1.0
	Conservative	Mark Nolan	7,431	15.5	1.0
	SNP	Iain White	5,054	10.5	4.7
	UKIP	James Beeley	545	1.1	New
Majority			2,184	4.6	4.1
Turnout			47,948	75.2	2.1
	Liberal Democrats hold		Swing	2.1

The constituency of 1950 to 1983 has an unusual electoral history, in that in two consecutive general elections it was gained by the party in third place at the previous election. In October 1974 the SNP leapfrogged Labour to defeat the Conservatives, and in 1979 Labour leapfrogged the Conservatives to beat the SNP. Furthermore, the constituency went the opposite way to the nation in two consecutive changes of government. In February 1974, the Conservatives gained it from Labour, though losing nationally, while in 1979 Labour regained the seat from the SNP, though losing nationally. Apart from Ynys Môn in Wales, East Dunbartonshire is the only seat to have been represented by the three main parties and the nationalists.

The October 1974 result was particularly unusual since it produced both the smallest majority in the country at that election, and the closest three-way result since 1945.

• East Dunbartonshire UK Parliament constituency (boundaries April 2005 – May 2024) at MapIt UK

55°58′34″N 4°12′40″W / 55.976°N 4.211°W / 55.976; -4.211