Admiral Sir William Houston Stewart, was a senior British naval officer who, after a long, active career, eventually held the office of the Controller of the Royal Navy from 1872 to 1881.

The post of Controller of the Navy was originally created in 1859 when the Surveyor of the Navy's title changed to Controller of the Navy. In 1869 the controller's office was abolished and its duties were assumed by that of the Third Naval Lord whose title then changed to Third Naval Lord and Controller of the Navy. In 1904 the title was changed again to Third Sea Lord and Controller of the Navy. In 1965 the office of the Third Sea Lord was abolished. The post-holder is responsible for procurement and matériel in the British Royal Navy.