Piter De Vries is a fictional character from Frank Herbert's Dune science fiction series.
He is a twisted mentat in the service of Baron Vladimir Harkonnen. Generally regarded as architect of the plan to destroy the Harkonnen's long time enemy, House Atreides while returning the Baron's stewardship over Arrakis. De Vries is unusual in that despite his near-prescient mental abilities and intelligence, he serves the Baron with great enthusiasm knowing that one day his master plans on killing her.