Barnet was a parliamentary constituency in what is now the London Borough of Barnet, which returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom.
The House of Commons (Redistribution of Seats) Act 1944 set up Boundaries Commissions to carry out periodic reviews of the distribution of parliamentary constituencies.
It also authorised an initial review to subdivide abnormally large constituencies (those exceeding an electorate of 100,000) in time for the 1945 election.
When seats were next redistributed, with effect from the February 1974 general election, the Greater London parts of the old constituency moved to the new Borough Constituency of Chipping Barnet.
The Elstree Rural District was transferred to the new County Constituency of South Hertfordshire.