What religious group did the Gunpowder Plot conspirators belong to?

The Gunpowder Plot conspirators belonged to the Catholic faith.

The 1605 plot was organized by English Catholics who hoped to end the religious restrictions imposed on Catholics after the English Reformation. Led by Robert Catesby, they planned to blow up the House of Lords during the State Opening of Parliament and replace King James I with a Catholic ruler.

Guy Fawkes, the conspirator who guarded the explosives, was also a committed Catholic. Several plotters had experienced recusancy laws, which punished Catholics for refusing to attend Church of England services. Their opposition was political as well as religious: they believed James had failed to deliver the toleration they had expected.

The conspirators were not Anglicans, Quakers, or Puritans. Anglicanism was the established Protestant religion, while Puritanism was a reform movement within English Protestantism; Quakerism did not emerge until the 1650s, decades after the plot. The failed conspiracy intensified anti-Catholic feeling and helped create the traditions later associated with Guy Fawkes Night.