Paul St. Clair Murphy (July 7, 1850 – November 9, 1931) was an American officer serving in the United States Marine Corps during the Spanish–American War.

He was one of 23 men to be awarded the Marine Corps Brevet Medal.

In 1893 he commanded the Marine detachment that guarded the exhibits for the World's Columbian Exposition in Chicago, Illinois.

In 1894 Commandant of the Marine Corps Colonel Heywood appointed Captain Murphy to lead the Marine Corps School of Application.

On October 10, 1910, he retired as a colonel on his own request, but returned to active duty from April 1917 to June 1920 during World War I.