The Conservative Party Archive (CPA) preserves the records of the Conservative Party’s central and national organisations (primarily what were formerly known before recent changes of name as Conservative Central Office and the National Union of Conservative and Unionist Associations) along with certain regional records. It is recognised by the Conservative Party as the official repository for its historic records and those of affiliated organisations, and receives new material on a regular basis.

The CPA was established as a source for academic study at the Bodleian Library in 1978 by an agreement made between the University of Oxford and the Conservative Party, and brought together surviving historic papers of the Party previously held in various locations including Newcastle University Library and the former Conservative Central Office in Smith Square, London. Since 1996, ownership and financial responsibility for the CPA has been vested in the Conservative Party Archive Trust.

Papers held in the Archive represent all three areas of Party organisation: elected, through the papers of the 1922 Committee, Shadow Cabinet and Chief Whip’s Office; voluntary, through the papers of the National Union of Conservative and Unionist Associations (including its Provincial Councils), and its successor the National Conservative Convention; and professional, through the working files of the Conservative Research Department, Conservative Central Office (including its Area Offices) and its successor, Conservative Campaign Headquarters and their many departments and committees. With few exceptions the Archive does not generally hold the private papers of individuals; rather it holds papers created by them in the course of carrying out their official Party duties. Although the parliamentary party constitutes the longest-established element of Conservative Party organisation, dating back to the Tory grouping in the House of Commons of the 17th century, the papers of the National Union are by far the oldest in the Archive, with a virtually unbroken series of minutes dating back to 1867. Conservative Central Office was established in 1870, but many records were lost to salvage drives during the War, and a number of moves by Central Office since led to the destruction of still more, particularly from the period before 1939. As a result, the archive consists predominantly of post-Second World War material. The records of the Conservative Research Department, housed separately from Conservative Central Office until 1979, date back to its foundation in 1929.