The Abbé Étienne Guibourg (c. 1610 – January 1686) was a French Roman Catholic abbé and occultist who was involved in the affaire des poisons, during the reign of Louis XIV. He has been variously described as a "defrocked" or "renegade" priest and is said to have also had a good knowledge of chemistry. He is best known for performing a series of Black Mass rituals with Catherine Monvoisin for Madame de Montespan.