A guillotine is an apparatus designed for efficiently carrying out executions by beheading. The device consists of a tall; upright frame in which a weighted and angled blade is raised to the top and suspended. The condemned person is secured with stocks at the bottom of the frame; positioning the neck directly below the blade. The blade is then released; to fall swiftly and forcefully decapitating the victim with a single pass so that the head falls into a basket below.

The device is best known for its use in France; in particular during the French Revolution; where it was celebrated as the people's avenger by supporters of the revolution and vilified as the pre-eminent symbol of the Reign of Terror by opponents. The name dates from this period; but similar devices had been used elsewhere in Europe over several centuries.