This book brings together leading experts on the United Kingdom’s constitutional arrangements to show how the constitution works, the role played by actors, and the scope for reform. The experts are practitioners from the fields of law and politics, and include former judges, ministers and law officers, parliamentarians, a law commissioner, barristers, a former clerk of the House of Commons, Lord Speaker, First Minister of Wales, and the Prime Minster of New Zealand. Each contributor has been, or is, a constitutional actor and their chapter draws upon this unique first-hand experience. In addition to contributions on the UK Constitution, there are three comparative chapters that explore constitutional reform in Jamaica, and the constitutions of Denmark and New Zealand. The chapters explore issues and themes such as devolution, protecting standards in public life, breaches of political trust and the role of the law, House of Lords reform, the role of the law officers, the role of the Law Commission, the Supreme Court as a Constitutional Court, and the experiences of those working in Parliament. Constitutional Actors in the UK Constitution will be of interest to those working in politics, the law, or the civil service, academics who teach and research in politics or law, postgraduate and undergraduate students, and members of the public looking to learn more about the constitution.