Addington graduated from Sandia High School in Albuquerque, New Mexico in 1974.
He was admitted to United States Naval Academy and attended beginning in Fall 1974, but dropped out during his freshman year.
He is a graduate of the Edmund A. Walsh School of Foreign Service at Georgetown University (B.S.F.S., summa cum laude) and holds a J.D. degree (with honors) from Duke University School of Law.
He was admitted to the bar in 1981.

Addington was an assistant general counsel for the Central Intelligence Agency from 1981 to 1984.

From 1984 to 1987 he was counsel for the House committees on intelligence and foreign affairs.
He served as a staff attorney on the joint US House–Senate committee investigation of the Iran-Contra affair as an assistant to Congressman Bill Broomfield (R-MI).
Books and news articles have said that he was one of the principal authors of a controversial minority report issued at the conclusion of the joint committee's investigation, which "defended President Reagan by claiming it was 'unconstitutional for Congress to pass laws intruding' on the 'commander in chief.'"
but in his opening remarks as he testified under subpoena before the House Judiciary Committee, Addington said that he had left the committee's service before the minority report was written and had no role in it.

Addington was also a special assistant for legislative affairs to President Ronald Reagan for one year in 1987, before becoming Reagan's deputy assistant.
From 1989 to 1992, Addington served as special assistant to Cheney who was then the Secretary of Defense, before being appointed by President George H. W. Bush and confirmed by the Senate as the Department of Defense's general counsel in 1992.
In 1993 and 1994, Addington was the Republican staff director of the Senate Intelligence Committee.
In 1994 and 1995, he headed a political action committee, the Alliance for American Leadership, set up to support Republican candidates for public office, with a principal focus on being a Presidential exploratory committee for Cheney, as the former Defense Secretary contemplated running for the 1996 Republican Presidential nomination.

From 1995 to 2001, he worked in private practice, for law firms Baker, Donelson, Bearman, Caldwell & Berkowitz and Holland & Knight, and the American Trucking Associations.
He also provided extensive assistance to Dick Cheney when the latter was chief executive officer of Halliburton Corporation and was in charge of vetting potential Presidential running mates for Texas governor George W. Bush, before he was officially his party's nominee for the White House and surprised many political observers by choosing Cheney himself to be his running mate.

On April 13, 2013, Addington was on a list released by the Russian Federation of Americans banned from entering the country over their alleged human rights violations.
The list was a direct response to the so-called Magnitsky list revealed by the United States the day before.

Addington served as group vice president for research at The Heritage Foundation and as Senior Vice President, General Counsel, and Chief Legal Officer at the National Federation of Independent Business.
Addington graduated from Sandia High School in Albuquerque, New Mexico in 1974. He was admitted to United States Naval Academy and attended beginning in Fall 1974, but dropped out during his freshman year. He is a graduate of the Edmund A. Walsh School of Foreign Service at Georgetown University (B.S.F.S., summa cum laude) and holds a J.D. degree (with honors) from Duke University School of Law. He was admitted to the bar in 1981.
Addington was an assistant general counsel for the Central Intelligence Agency from 1981 to 1984.
From 1984 to 1987 he was counsel for the House committees on intelligence and foreign affairs. He served as a staff attorney on the joint US House–Senate committee investigation of the Iran-Contra affair as an assistant to Congressman Bill Broomfield (R-MI). Books and news articles have said that he was one of the principal authors of a controversial minority report issued at the conclusion of the joint committee's investigation, which "defended President Reagan by claiming it was 'unconstitutional for Congress to pass laws intruding' on the 'commander in chief.'" but in his opening remarks as he testified under subpoena before the House Judiciary Committee, Addington said that he had left the committee's service before the minority report was written and had no role in it.
Addington was also a special assistant for legislative affairs to President Ronald Reagan for one year in 1987, before becoming Reagan's deputy assistant. From 1989 to 1992, Addington served as special assistant to Cheney who was then the Secretary of Defense, before being appointed by President George H. W. Bush and confirmed by the Senate as the Department of Defense's general counsel in 1992. In 1993 and 1994, Addington was the Republican staff director of the Senate Intelligence Committee. In 1994 and 1995, he headed a political action committee, the Alliance for American Leadership, set up to support Republican candidates for public office, with a principal focus on being a Presidential exploratory committee for Cheney, as the former Defense Secretary contemplated running for the 1996 Republican Presidential nomination.
From 1995 to 2001, he worked in private practice, for law firms Baker, Donelson, Bearman, Caldwell & Berkowitz and Holland & Knight, and the American Trucking Associations. He also provided extensive assistance to Dick Cheney when the latter was chief executive officer of Halliburton Corporation and was in charge of vetting potential Presidential running mates for Texas governor George W. Bush, before he was officially his party's nominee for the White House and surprised many political observers by choosing Cheney himself to be his running mate.
On April 13, 2013, Addington was on a list released by the Russian Federation of Americans banned from entering the country over their alleged human rights violations. The list was a direct response to the so-called Magnitsky list revealed by the United States the day before.
Addington served as group vice president for research at The Heritage Foundation and as Senior Vice President, General Counsel, and Chief Legal Officer at the National Federation of Independent Business.
David Addington