Robert Keyes was a member of the group of provincial English Catholics who planned the failed Gunpowder Plot of 1605, a conspiracy to assassinate King James I by blowing up the House of Lords during the State Opening of Parliament on 5 November 1605. He was the sixth man to join the plot.

The Gunpowder Plot of 1605, in earlier centuries often called the Gunpowder Treason Plot or the Jesuit Treason, was an unsuccessful attempted regicide against King James I by a group of English Catholics led by Robert Catesby who considered their actions attempted tyrannicide and who sought regime change in England after decades of religious persecution.