The territory of the Council is about four-fifths of Buckinghamshire (the ceremonial county, which also includes the City of Milton Keynes) and has about two-thirds of its population.

The county was reformed in 1974, when it ceded Slough, Eton and nearby villages to Berkshire.

Elected county councils were created in 1889 under the Local Government Act 1888, taking over administrative functions which had previously been performed by unelected magistrates at the quarter sessions.

[7] Buckinghamshire was redesignated as a non-metropolitan county in 1974 under the Local Government Act 1972, which also transferred Slough, Eton, and nearby villages to Berkshire.

They were also reorganised as part of the 1974 reforms into five non-metropolitan districts: Aylesbury Vale, Chiltern, Milton Keynes, South Bucks (called 'Beaconsfield' until 1980), and Wycombe.

[10] The City of Milton Keynes remains part of the ceremonial county of Buckinghamshire for the purposes of lieutenancy.

The county council proposed abolishing the four remaining districts in its area and having one unitary authority.

[13] The government ultimately decided to pursue the single unitary authority as proposed by the county council.

The three southern districts considered seeking a judicial review of the government's decision, but ultimately decided against.

[30] As at December 2024, the composition of the council was:[31] The Liberal Democrats and Wycombe Independents sit together as the "Alliance Grouping".

It houses various collections and historical records within Buckinghamshire as well as Milton Keynes and the Paralympics.

[38] The logo of the new Buckinghamshire Council consists of a blue circle with a white swan flying above hills, with a row of three trees.