The Freedom of Information Act 2000 (c. 36) (FOIA) is an act of the Parliament of the United Kingdom that creates a public right of access to information held by public authorities. It is the implementation of freedom of information legislation in the United Kingdom on a national level. Its application is limited in Scotland (which has its own freedom of information legislation) to UK Government offices located in Scotland. The act implements a manifesto commitment of the Labour Party in the 1997 general election, developed by David Clark as a 1997 White Paper. The final version of the act was criticised by freedom of information campaigners as a diluted form of what had been proposed in the White Paper. The full provisions of the act came into force on 1 January 2005. The act was the responsibility of the Lord Chancellor's Department (now renamed the Ministry of Justice). However, freedom of information policy is now the responsibility of the Cabinet Office. The act led to the renaming of the Data Protection Commissioner (set up to administer the Data Protection Act 1998), who is now known as the Information Commissioner. The Office of the Information Commissioner oversees the operation of the act.

A second freedom of information law is in existence in the UK, the Freedom of Information (Scotland) Act 2002 (asp 13). It was passed by the Scottish Parliament in 2002, to cover public bodies over which the Holyrood parliament, rather than Westminster, has jurisdiction. For these institutions, it fulfils the same purpose as the 2000 Act.

Around 120,000 requests were made in the first year that the act was in force. Private citizens made 60% of them, with businesses and journalists accounting for 20% and 10% respectively. However, requests from journalists tended to be more complex, and, consequently, more expensive. They accounted for around 10% of initial FoI requests made to central government, but 20% of the costs of officials' time in dealing with the requests. The act cost £35.5 million in 2005.

The act implements what was a manifesto commitment of the Labour Party in the 1997 general election. Before its introduction, there had been no right of access to government by the general public, merely a limited voluntary framework for sharing information.

The act was preceded by a 1998 white paper, Your Right to Know, by David Clark. The White paper was met with widespread enthusiasm, and was described at the time as being "almost too good to be true" by one advocate of freedom of information legislation. The final act was substantially more limited in scope than the initial white paper.

A draft bill was published in May 1999; the bill was extensively debated in the House of Commons and the House of Lords, and received royal assent in November 2000.

The FOIA modernised the Public Records Act 1958. This act gave the public a general right to access all types of recorded information held by public authorities, much greater than was previously allowed. The FOIA was mainly concerned with the management and preservation of public records.

The FOIA reduced the 30-year rule to a 20-year rule, meaning records would be made public earlier. This gave the public the ability to access more recent records without sacrificing national security or personal privacy.