James Benson Irwin (March 17, 1930 – August 8, 1991) was an American astronaut, aeronautical engineer, test pilot, and a United States Air Force pilot. He served as Lunar Module pilot for Apollo 15, the fourth human lunar landing. He was the eighth person to walk on the Moon.

Irwin was born March 17, 1930, in Pittsburgh, Pennsylvania, of Scottish, German (maternal side) and Irish descent, to parents James William Irwin (1896–1978), a U.S. Army World War I veteran, and Elsa Mathilda Irwin (née Strebel; 1898–1993) who had German ancestry. Irwin's paternal grandparents emigrated to the U.S. from Altmore Parish at Pomeroy in County Tyrone, Ireland (now Northern Ireland) around 1859.

In 1941, James Irwin lived at 6006 Grand Boulevard in New Port Richey FL and attended Pierce Elementary School (now the site of the New Port Richey Public Library and City Hall). While he was in the 6th grade, James was also enrolled in 7th grade classes at Gulf High School due to his advanced abilities. He is listed as a 7th grader in the 1942 Gulf High School yearbook. Throughout his life, James Irwin frequently returned to New Port Richey, where he was a member of and attended the First Baptist Church. The Astronaut Who Called New Port Richey Home

At about the age of 12, he informed his mother about his desire to go to the Moon, letting her know that he might be the first person to do so (he ended up being the eighth). He graduated from East High School in Salt Lake City, Utah in 1947. He received a Bachelor of Science degree in naval science from the United States Naval Academy in 1951, and Master of Science degrees in aeronautical engineering and instrumentation engineering from the University of Michigan in 1957.

He received initial flight training at Hondo Air Base and follow-up training at Reese Air Force Base, Texas. He graduated from the Air Force Experimental Flight Test Pilot School (Class 60C) in 1961, and the Aerospace Research Pilot School in 1963 (Class IV). Prior to joining NASA, he was chief of the Advanced Requirements Branch at Headquarters Air Defense Command. During his time in the United States Air Force he received the Air Force Distinguished Service Medal and two Air Force Commendation Medals. He also received an Air Force Outstanding Unit Award while with the 4750th Training Wing.

Irwin was also a developmental test pilot for the Lockheed YF-12, the Mach 3 fighter-interceptor variant which preceded the SR-71 Blackbird. His first flight of that aircraft was on the day that one of his five children was born.

In 1961, a student pilot that Irwin was training crashed the plane they were flying on a training mission. They both survived, but Irwin suffered compound fractures, amnesia, and nearly lost a leg. John Forrest, a U.S. Air Force orthopedic surgeon, was instrumental in preventing the amputation of Irwin's leg.

During his military service, he accumulated more than 7,015 hours flying time, of which 5,300 hours were in jet aircraft.