| Office: | 12th Legal Adviser of the Department of State |
| Term Start: | January 21, 1975 |
| Term End: | January 20, 1977 |
| Preceded: | Carlyle E. Maw |
| Succeeded: | Herbert J. Hansell |
| Birth Date: | 1919 |
| Death Date: | 2001 |
| Birth Place: | Halifax, Virginia |
| Education: | Hampden-Sydney College University of Virginia |
Monroe Leigh (1919–2001) was a prominent American political philosopher and diplomat. He was born in Halifax, Virginia, in 1919. He graduated from Hampden-Sydney College in 1940 and earned a law degree from the University of Virginia, serving as editor of the Virginia Law Review. His time in law school was interrupted by service in the Army Air Forces during World War II.
He served as a legal adviser for the United States Defense Department and was picked by Henry Kissinger to serve as Legal Adviser of the Department of State. He was also NATO mission envoy, and president of the American Society of International Law. He was a prolific writer on the subject of international law, with his influential criticism of the United States' refusal to sign the Rome Statute of the International Criminal Court being published in 2000, the year before he died.