Gunpowder Plot, in English history, a conspiracy to blow up King James I and Parliament in 1605. It was planned by several prominent English Catholics who resented James's strict enforcement of anti-Catholic laws. Thirty-six barrels of gunpowder were placed in a cellar under the House of Lords, where James was to address Parliament on November 5.

The plot was discovered, and one of the conspirators, Guy Fawkes, was arrested as he entered the cellar before the planned explosion. He and most of his associates were put to death. On November 5, English children celebrate Guy Fawkes Day by shooting firecrackers and burning effigies of Fawkes.