John Allsebrook Simon, 1st Viscount Simon, was a British politician who held senior Cabinet posts from the beginning of the First World War to the end of the Second World War. He is one of three people to have served as Home Secretary, Foreign Secretary and Chancellor of the Exchequer, the others being Rab Butler and James Callaghan.

The Secretary of State for the Home Department, more commonly known as the Home Secretary, is a senior minister of the Crown in the Government of the United Kingdom and the head of the Home Office. The position is a Great Office of State, making the home secretary one of the most senior and influential ministers in the government. The incumbent is a statutory member of the British Cabinet and National Security Council.