Robert Keyes (1565–1606) 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.

[9] Father Oswald Tesimond claimed that Keyes had "tasted persecution himself, having lost his goods because of it"[10] while historian and author Cyril Northcote Parkinson's image of him was of a "desperate man, ruined and indebted".

Several conspirators expressed concerns about the safety of fellow Catholics who would be at Parliament on the day of the planned explosion; Keyes was particularly worried about Lord Mordaunt, his wife's employer.

[12] Thomas Percy was concerned for his patron and kinsman, the Earl of Northumberland, and the Lords Vaux, Montagu, Monteagle and Stourton were also mentioned.

Keyes's suggestion to warn Lord Mordaunt was treated by Catesby with derision, when he answered that "he would not for the chamber full of diamonds acquaint him with the secret, for that he knew he could not keep it.

[14] They were visited late that evening by Fawkes (in charge of the explosives beneath the House of Lords) who collected a watch left by Percy, for timing the fuse.

After he and Rookwood had caught up with Catesby, Percy, Thomas Bates, and John and Christopher Wright, Keyes left the group, and headed instead for Lord Mordaunt's house at Drayton, where he went to ground.

[20] Keyes made no attempt to excuse his actions, claiming that "death was as good now as at any other time",[21] preferable to living "in the midst of so much tyranny".