Scott was born June 6, 1932, at Randolph Field (for which he received his middle name) near San Antonio, Texas. His father was Tom William Scott (1902–1988), a fighter pilot in the United States Army Air Corps who would rise to the rank of brigadier general; his mother was the former Marian Scott (née Davis; 1906–1998). Scott lived his earliest years at Randolph Field, where his father was stationed, before moving to an air base in Indiana, and then in 1936 to Manila in the Philippines, then under U.S. rule. David remembered his father as a strict disciplinarian. The family returned to the United States in December 1939. By the time of the attack on Pearl Harbor in 1941, the family was living in San Antonio again; shortly thereafter Tom Scott was deployed overseas.

David Scott was active in the Boy Scouts of America, achieving its second-highest rank, Life Scout. With Tom Scott assigned to March Air Force Base near Riverside, California, David attended Riverside Polytechnic High School, where he joined the swimming team and set several state and local records. Before David could finish high school, Tom Scott was transferred to Washington, D.C., and after some discussion as to whether he should remain in California to graduate, David attended Western High School in Washington, graduating in June 1949.

Scott still wanted to fly, and wanted to be commissioned in the newly-established Air Force. The Air Force Academy was founded in 1954, the year Scott graduated from West Point; an interim arrangement had been made whereby a quarter of West Point and United States Naval Academy graduates could volunteer to be commissioned as Air Force officers. Earning a Bachelor of Science degree in military science, Scott graduated 5th in his class of 633, and was commissioned in the Air Force.

Scott did six months’ primary pilot training at Marana Air Base in Arizona, beginning there in July 1954. He completed Undergraduate Pilot Training at Webb Air Force Base, Texas, in 1955, then went through gunnery training at Laughlin Air Force Base, Texas, and Luke Air Force Base, Arizona.

From April 1956 to July 1960, Scott flew with the 32d Tactical Fighter Squadron at Soesterberg Air Base, Netherlands, flying F-86 Sabres and F-100 Super Sabres. The weather there was often poor, and Scott’s piloting skills were tested. Once, he had to land his plane on a golf course after a flameout. On another, he barely made it to a Dutch base on the edge of the North Sea. Scott served in Europe during the Cold War and tensions were often high between the U.S. and Soviet Union. During the Hungarian Revolution of 1956, his squadron was placed on highest alert for weeks, but was stood down without going into combat.

In 1959 Scott married his first wife, Ann Ott. He had two children with her: Tracy (born 1961) and Douglas (born 1963). In 2000, it was reported that he was engaged to British TV presenter Anna Ford; at the time he was still married to Ann Scott, although separated. His relationship with Ford had begun in 1999. By 2001, Scott and Ford had separated. He subsequently married Margaret Black, former vice-chairman of Morgan Stanley. David Scott and Margaret Black-Scott reside in Los Angeles.

Scott hoped to advance his career by becoming a test pilot, to be trained at Edwards Air Force Base. He was counseled that the best way to get into test pilot school was to gain a graduate degree in aeronautics. Accordingly, he applied to the Massachusetts Institute of Technology (MIT), and was accepted. He received both a Master of Science degree in Aeronautics/Astronautics and the degree of Engineer in Aeronautics/Astronautics (the E.A.A. degree) from MIT in 1962.

Scott reported to the U.S. Air Force Test Pilot School at Edwards in July 1962. The commandant of the school was Chuck Yeager, first person to break the sound barrier, who Scott idolized; Scott got to fly several times with him. Scott graduated top pilot in his class. He was selected for the Aerospace Research Pilot School, also at Edwards, where those intended as Air Force astronauts were trained. There he learned how to control aircraft, such as the F-104 Starfighter, at altitudes of up to 100,000 feet (30,000 m).

In applying in 1963 to be part of the third group of astronauts to be selected, Scott intended only a temporary detour from a mainstream military career; he expected to fly in space a couple of times and then return to the Air Force. He was accepted as one of the fourteen Group 3 astronauts later that year.

On March 16, 1966, Armstrong and Scott were launched into space, a flight originally planned to last three days. The Agena rocket with which they were to dock had been launched an hour and forty minutes earlier. They carefully approached and docked with the Agena, the first docking ever accomplished in space. After the docking, there was unexpected movement by the joined craft. Mission Control was out of touch during this portion of the orbit, and the astronauts’ belief that the Agena was causing the problem proved incorrect, for once they performed an emergency undocking, the spin only got worse. With the spacecraft spinning, there was risk of the astronauts blacking out or the Gemini vehicle disintegrating. The problem was one of the craft’s OAMS thrusters firing unexpectedly; the crew shut down those thrusters, and Armstrong activated the Reaction Control System thrusters to negate the spin. The RCS thrusters were to be used for reentry, and the mission rules said if they were activated early, Gemini 8 had to return to Earth. Gemini 8 splashed down in the Western Pacific on the day of launch; the mission lasted only ten hours, and the early termination meant that Scott’s spacewalk was scrubbed.

Deputy Administrator Robert Seamans presented Scott and Armstrong the NASA Exceptional Service Medal in 1966 for their Gemini flight. Scott was also awarded the Distinguished Flying Cross for the Gemini 8 flight. Vice President Spiro Agnew presented the Apollo 9 crew with the NASA Distinguished Service Medal. At the ceremony, Agnew said, “I am proud that America has forged to the forefront and established the leadership in space to match our new leadership on Earth.” Scott received the Air Force Distinguished Service Medal for the Apollo 9 mission.

Scott’s Apollo assignment was as backup senior pilot/navigator for what would become known as Apollo 1, scheduled for launch in February 1967, with Jim McDivitt as backup commander and Russell Schweickart as pilot. In that capacity, they spent much of their time at North American Rockwell’s plant in Downey, California, where the command and service module (CSM) for that mission was under construction.

By January 1967, Scott’s crew had been assigned as prime crew for a subsequent Apollo mission, and were at Downey on January 27 when a fire took the lives of the Apollo 1 prime crew during a pre-launch test. During the fire, the inward-opening hatch had proved impossible for the astronauts to open, and Scott’s post-fire assignment, with all flights put on hold amid a complete review of the Apollo program, was to serve on the team designing a simpler, outward-opening hatch.

After the pause, Scott’s crew was assigned to Apollo 8, intended to be an Earth-orbit test of the full Apollo spacecraft, including the Lunar Module (LM). There were delays in the development of the lunar module and in August 1968, NASA official George Low proposed that if Apollo 7 in October went well, Apollo 8 should go to lunar orbit without a Lunar Module, so as not to hold up the program. The Earth-orbit test would become Apollo 9. McDivitt was offered Apollo 8 by Slayton, but turned it down on behalf of his crew (who fully agreed), preferring to wait for Apollo 9, which would involve extensive testing of the spacecraft and was dubbed “a test pilot’s dream”.

The planned February 28, 1969 launch date was postponed as all three astronauts had head colds, and NASA was wary of medical issues in space after problems on Apollo 7 and 8. The launch took place on March 3, 1969. Within hours of launch, Scott had performed a maneuver essential to the lunar landing by piloting the CSM Gumdrop away from the S-IVB rocket stage, then turned Gumdrop around and docked with the LM Spider still attached to the S-IVB, before the combined spacecraft separated from the rocket.

The remainder of the mission was devoted to tests of the command module, mostly performed by Scott; Schweickart called these days “Dave Scott’s mission”; McDivitt and Schweickart had much time to observe the Earth as Scott worked. The mission stayed in space one orbit longer than planned due to rough seas in the Atlantic Ocean recovery zone. Apollo 9 splashed down on March 13, 1969 less than four nautical miles (7 km) from the helicopter carrier USS Guadalcanal, 180 miles (290 km) east of the Bahamas.

Scott was deemed to have performed his duties well, and on April 10, 1969, was named backup commander of Apollo 12, with Al Worden as command module pilot and James Irwin as lunar module pilot. McDivitt had chosen to go into NASA management, and Slayton had seen Scott as a potential crew commander; Worden and Irwin were working on the support crews for Apollo 9 and 10, respectively. Schweickart was ruled out due to the space sickness episode. This put the three in line to be the prime crew for Apollo 15. Scott’s status as backup commander of the next flight allowed him to sit in the Mission Control room as Apollo 11, with his old crewmate Armstrong in command, landed on the Moon. That Scott, Worden and Irwin would be the crew of Apollo 15 was announced on March 26, 1970.

Apollo 15 launched from Kennedy Space Center’s Launch Complex 39A on July 26, 1971. The outward flight to the Moon’s orbit saw only minor difficulties, and the mission entered lunar orbit without incident. The descent to the Moon by the LM Falcon, with Scott and Irwin aboard, took place on the late afternoon of July 30, with Scott as commander attempting the landing. Despite difficulties caused by the computer-controlled flight path being to the south of what was planned, Scott assumed manual control for the final descent, and successfully landed the Falcon within the designated landing zone.

Apollo 15 splashed down in the Pacific Ocean north of Honolulu on August 7, 1971. The first crew to land on the Moon and not be quarantined on return, the astronauts were flown to Houston, and after debriefing, were sent off on the usual circuit of addresses to Congress, celebrations and foreign trips that met returning Apollo astronauts. Scott regretted the lack of quarantine, which he felt would have given them time to recover from the flight, as the demands on their time were heavy.

The crew had arranged with a friend named Horst Eiermann to carry postal covers to the Moon in exchange for about $7,000 for each astronaut. Slayton had issued regulations that personal items taken in spacecraft be listed for his approval; this was not done for the covers through an error. Scott carried the covers into the CM in his spacesuit; they were transferred to the LM en route to the Moon, and landed there with the astronauts. Scott sent 100 of them to Eiermann, and in late 1971, against the astronauts’ wishes, the covers were offered for sale by West German stamp dealer Hermann Sieger. The astronauts returned the money, but in April 1972, Slayton learned of the unauthorized covers, and had Scott, Worden and Irwin removed as backup crew members for Apollo 17. The matter became public in June 1972, and the astronauts were reprimanded for poor judgment by NASA and the Air Force the following month. The covers that the crew still had were initially impounded by NASA but were in 1983 returned to the astronauts in an out-of-court settlement, as the government felt it could not successfully defend the lawsuit, and that NASA either authorized the covers to be flown or was aware of them.

Agnew also gave the Apollo 15 crew the NASA Distinguished Service Medal. Scott earned his second Air Force Distinguished Service Medal for Apollo 15. On September 15, 1971, the city of Chicago hosted the Apollo 15 crew in a parade attended by more than 200,000 people. Mayor Daley presented the crew with honorary citizenship medals. On August 25, 1971, the Apollo 15 crew were honored with a ticker-tape parade in New York City. The city bestowed them with gold medals. Later that day, U.N. Secretary General Thant awarded the trio the first United Nations Peace Medal. At the Air Force Association’s annual dinner dance in September 1971, the Apollo 15 crew were presented with the David C. Schilling Trophy, the association’s top flight award. Scott presented the Air Force and Air Force Association with items they flew to the Moon: sheet music of “Into the Wild Blue Yonder” and a U.S. Air Force flag. The Apollo 15 crew and Robert Gilruth (director of the Manned Spacecraft Center) were awarded the 1971 Robert J. Collier Trophy, an annual award for the greatest achievement in aeronautics or astronautics. Scott received the De la Vaulx Medal, the Gold Space Medal, and the V.M. Komorav Diploma from Fédération Aéronautique Internationale for 1971 for his role in the Apollo 15 flight. Scott was awarded his third NASA Distinguished Service Medal in 1978.

Scott, Worden and Irwin were granted Honorary Doctorates of Astronautical Science from the University of Michigan in 1971. Scott was awarded an honorary doctor of science and technology degree from Jacksonville University in 2013. It was the first honorary degree bestowed by the university.

In his role with Apollo-Soyuz, Scott traveled to Moscow, leading a team of technical experts. There he met the commander of the Soviet part of the mission, Alexei Leonov, with whom he would later write a joint autobiography. In 1973, Scott was offered the job of deputy director of NASA’s Dryden Flight Research Center, located at Edwards, a place Scott had long loved. This allowed Scott to fly aircraft that reached the edge of space, and let him renew his acquaintance with the retired Chuck Yeager who was there as a consulting test pilot, and to whom Scott granted flying privileges.

On April 18, 1975, at age 42, Scott became the Center Director at Dryden. This was a civilian appointment, and to accept it, Scott retired from the Air Force in March 1975. Kraft wrote in his memoirs that Scott’s appointment “pissed off Deke to his eyebrows”. Scott found the work interesting and exciting, but with budget cuts and the forthcoming end of approach and landing tests for the Space Shuttle, in 1977 he decided it was time to leave NASA and retired from the agency on September 30, 1977.

Scott was a commentator for British television on the first Space Shuttle flight (STS-1) in April 1981. He also was a consultant on the film Apollo 13 and for the 1998 HBO miniseries From the Earth to the Moon, in which he was portrayed by Brett Cullen. Scott consulted on the 3D IMAX film, Magnificent Desolation (2005), showing Apollo astronauts on the Moon, and produced by Tom Hanks and the IMAX Corporation. He is one of the astronauts featured in the 2007 book and documentary In the Shadow of the Moon.

In 1982, Scott was inducted with nine other Gemini astronauts into the International Space Hall of Fame in the New Mexico Museum of Space History. Along with 12 other Gemini astronauts, Scott was inducted into the U.S. Astronaut Hall of Fame in 1993.

Entering the private sector, Scott founded Scott Science and Technology, Inc. In the late 1970s and the 1980s, Scott worked on several government projects, including designing the astronaut training for a proposed Air Force version of the Space Shuttle. One of Scott’s firms went out of business after the 1986 Challenger disaster; though the company played no part in the disaster, subsequent redesign of parts of the shuttle eliminated Scott’s firm’s role. After Challenger, Scott served four years on the Commercial Space Transportation Advisory Committee, formed to advise the Secretary of Transportation on the possible conversion of ICBMs to launch vehicles. In 1992, Scott was found by a Prescott, Arizona, court to have defrauded nine investors in a partnership organized by him. He was ordered to pay roughly $400,000 to investors in the partnership, which was to create technology to prevent aircraft mechanical breakdowns, but which was never developed.

In 2003–2004 he was a consultant on the BBC TV series Space Odyssey: Voyage To The Planets. In 2004, he and Leonov began work on a dual biography/history of the “Space Race” between the United States and the Soviet Union. The book, Two Sides of the Moon: Our Story of the Cold War Space Race, was published in 2006. Armstrong and Hanks both wrote introductions to the book. Scott has worked on the Brown University science teams for the Chandrayaan-1 lunar orbiter. For NASA, he has worked on the 500-Day Lunar Exploration Study and as a collaborator on the research investigation entitled “Advanced Visualization in Solar System Exploration and Research (ADVISER): Optimizing the Science Return from the Moon and Mars”.

Scott had taken two Bulova timepieces, a wrist watch and a stopwatch, with him to the Moon without advance authorization from Slayton. Scott wore the wrist watch on the third EVA, after his NASA-issued Omega Speedmaster lost its crystal. He sold the Bulova watch in 2015 for $1.625 million, after which the company marketed similar timepieces, whose accompanying material mentioned Scott and Apollo 15. Scott sued in federal court in 2017, alleging Bulova and Kay Jewelers were wrongfully using his name and image for commercial purposes, and the following year a federal magistrate ruled he could proceed on some of his claims.