Christopher Nugent was born in 1838 in County of Craven, Ireland, and later immigrated to the United States. He enlisted in the U.S. Navy in 1854, and served as a ship's boy aboard Commodore Matthew C. Perry's ship on his second visit to Japan in 1854. After serving for four years in the Navy, Nugent enlisted in the U.S. Marine Corps on February 8, 1858, in Charleston, Massachusetts, and served as Orderly Sergeant aboard the steamer USS Fort Henry during the U.S. Civil War. He was awarded the Medal of Honor on April 16, 1864, for his actions aboard the USS Fort Henry at Crystal River, Florida, on June 15, 1863, and he received an honorably discharge from the Marine Corps on October 9, 1865. During the war he also served aboard the steamer USS Tioga, at the Marine Base at Portsmouth, New Hampshire, and aboard the sloop-of-war USS Vandalia. He died on May 6, 1898, and was buried at the Saint Raymond Cemetery in Bronx, New York.

His Medal of Honor Citation reads

Serving on board the U.S.S. FORT HENRY, Crystal River, Florida, 15 June 1863. Reconnoitering on the Crystal River on this date and in charge of a boat from the FORT HENRY, Orderly Sergeant Nugent ordered an assault upon a rebel breastwork fortification. In this assault, the orderly sergeant and his comrades drove a guard of 11 rebels into the swamp, capturing their arms and destroying their camp equipage while gallantly withholding fire to prevent harm to a woman among the fugitives. On 30 July 1863, he further proved his courage by capturing a boat off Depot Key, Florida containing two men and a woman with their baggage.