Spencer Perceval was shot in the lobby of the House of Commons, becoming the only British prime minister to be assassinated.

Spencer Perceval was a British statesman and barrister who was Prime Minister of the United Kingdom from October 1809 until his assassination in May 1812. He is the only British prime minister to have been assassinated, and the only solicitor-general or attorney-general to have become prime minister.

On 11 May 1812, at about 5:15 pm, Spencer Perceval, the prime minister of the United Kingdom of Great Britain and Ireland, was shot dead in the lobby of the House of Commons by John Bellingham, a Liverpool merchant with a grievance against the government. Bellingham was detained; four days after the murder, he was tried, convicted and sentenced to death. He was hanged at Newgate Prison on 18 May, one week after the assassination and one month before the start of the War of 1812. Perceval remains the sole British prime minister to have been assassinated.

The House of Commons is the lower house of the Parliament of the United Kingdom. Like the upper house, the House of Lords, it meets in the Palace of Westminster in London, England. The House of Commons is an elected body consisting of 650 members known as members of Parliament (MPs), who are elected to represent constituencies by the first-past-the-post system and hold their seats until Parliament is dissolved.

The prime minister of the United Kingdom is the head of government of the United Kingdom. The prime minister advises the sovereign on the exercise of much of the royal prerogative, chairs the Cabinet, and selects its ministers. Modern prime ministers hold office by virtue of their ability to command the confidence of the House of Commons, so they are invariably members of Parliament.