William Montagu, 3rd Duke of Manchester (1737-1819), was a British nobleman known for his role in the House of Lords. He inherited the title from his father, the 2nd Duke, and was involved in various political and social activities during his lifetime. The Duke was also a prominent landowner, managing estates in England and Scotland. In addition to his political career, the 3rd Duke was known for his interest in the arts and culture. He was a patron of several artists and contributed to the development of British society during the late 18th and early 19th centuries. His legacy includes the continued prominence of the Montagu family in British history.