The Joint Committee on the National Security Strategy (JCNSS) is a joint committee of the Parliament of the United Kingdom, formed to "monitor the implementation and development" of the United Kingdom Government's National Security Strategy". It was first established in the 2005–2010 Parliament, and was reappointed in December 2010 and December 2015. The committee comprises a maximum of 12 members of the House of Commons and 10 members of the House of Lords.

The committee’s terms of reference are “to consider the National Security Strategy”. It has said that it does not wish to duplicate the work of other select committees, and instead intends to draw on their work. The Committee "scrutinises the structures for Government decision-making on National Security, particularly the role of the National Security Council (NSC) and the UK's National Security Adviser (NSA)."

As of June 2025, the membership of the committee is as follows:

The committee published its first report First Review of the National Security Strategy 2010 on 8 March 2012. The report addresses the National Security Strategy, the National Security Council (and the secretariat which supports it), and the National Security Adviser. It was agreed unanimously. The committee welcomed the National Security Strategy but said that it was work in progress and needed to be improved. In a press release sent out with the report it said that:

It also said that the government's unwillingness to provide it with all the information it had asked for about the National Security Risk Assessment means that it was unable to give Parliament any assurances about its adequacy. The committee expressed concerns that the "National Security Council's oversight of security issues is not sufficiently broad and strategic", given that it was deeply involved in operations in Libya and failed to discuss the national security implications of the Eurozone crisis or the possibility of Scottish independence.

The JCNSS published the government response to its first report on 11 July 2012, along with a two-page report summarising the committee's concerns about the response. The committee said that it welcomed the government response and the government's commitment to providing it with more information in future, but said that the government had failed to:

The committee said that the government needed to start to map out its programme for the next NSS immediately. It also called on the Government to supply it with an indicative programme for producing and consulting on the next NSS.

The government responded in November 2012 and said that it was: