Valentine McGillycuddy (1849-1939) was a surgeon in the U.S. Army and was an Indian Agent at Pine Ridge Reservation.

Valentine Trant McGillycuddy was born on February 14, 1849 in Racine, Wisconsin. He graduated from the Detroit Medical College in a degree of Doctor of Medicine in 1869. In 1871, he served on the U.S. Boundary Survey Commission for the U.S. government as a topographer, and was in this position until 1874. He was assigned as the topographical engineer and physician to the Jenney Black Hills expedition in 1875, and then in 1876, he was appointed surgeon of the 2nd U.S. Calvary. In this position, he oversaw service in South Dakota, Wyoming, Nebraska, and Montana, and was the attending physician when Crazy Horse, the Indian chief, was fatally wounded.

In 1879, McGillycuddy was appointed Indian Agent at the Pine Ridge Reservation. While trying to bridge relationships between the whites and Indians, he received criticism, but establised an Indian police force and a boarding school for the Native American children. He left the position in 1886, and helped in the business affairs of several companies in Rapid City, South Dakota. After 1912, he moved to California and practiced medicine until he retired. McGillycuddy died in Berkeley, California on June 06, 1939.