Sir Percy Joseph Sillitoe KBE DL (22 May 1888 – 5 April 1962) was a chief constable of several police forces.

In 2009, it was revealed that he had had a relationship with Mary Museba, a local woman of the Bemba people, from the Abercorn District of Northern Rhodesia; they had a son, John Alexander Sillitoe, born in 1918.

During his time as chief constable of Glasgow, he was also credited with the introduction of wireless radios allowing communication between headquarters and vehicles (which had previously relied completely upon the use of police boxes), use of civilians in police-related roles, and the introduction of compulsory retirement after 30 years service.

[6] In 1944 Sillitoe was made the chief constable of Kent and he employed Barbara Denis de Vitré to lead the women's force.

His reputation was damaged by the 1951 defection to the Soviet Union of the spies Guy Burgess and Donald Duart Maclean, and by the investigation afterwards, which showed that MI5 had been unaware and slow to act.