This article is about the religious office in historic Christianity. For other uses, see Inquisitor (disambiguation).

An inquisitor was an official in an inquisition, an organisation or program intended to eliminate heresy and other things frowned on by the Roman Catholic Church. Literally, an inquisitor is one who "searches out" or "inquires" (Latin inquirere < quaerere, "to seek").

The chief inquisitor of an inquisition was often called the Grand Inquisitor.

Prominent inquisitors

Some of the more well-known inquisitors throughout history include:

• Bernard Gui
• Diego Deza
• Fabio Chigi (later Pope Alexander VII)
• Francisco Jimenez de Cisneros
• Francisco Peña
• Konrad von Marburg
• Pedro de Arbués
• Tomás de Torquemada
• Nicolas Eymeric author of the The Directorium Inquisitorum