| Image | Name | Tenure | SecDef(s) served under | President(s) served under | 
| File:Streuve Hensel (Assistant Secretary of the Navy).jpg | H. Struve Hensel | August 17, 1953 – March 4, 1954 | Charles Erwin Wilson | Dwight Eisenhower | 
| File:Wilber Marion Brucker (cropped).jpg | Wilber M. Brucker | April 23, 1954 – July 20, 1955 | 
| File:Blank.svg | Mansfield D. Sprague | October 6, 1955 – February 27, 1957 | 
| File:Blank.svg | Robert Dechert | February 28, 1957 – July 15, 1959 | Charles Erwin Wilson Neil H. McElroy
 | 
| File:Blank.svg | J. Vincent Burke Jr. | September 14, 1959 – January 20, 1961 | Neil H. McElroy Thomas S. Gates
 | 
| File:CyrusVanceSoS.jpg | Cyrus Vance | January 29, 1961 – June 30, 1962 | Robert S. McNamara | John F. Kennedy | 
| File:John T. McNaughton (cropped).jpg | John McNaughton | July 5, 1962 – June 25, 1964 | John F. Kennedy Lyndon B. Johnson
 | 
| File:Blank.svg | Leonard Niederlehner (Acting) | July 1, 1964 – September 19, 1966 | Lyndon B. Johnson | 
| File:Paul Warnke 1983 (cropped).jpg | Paul Warnke | October 3, 1966 – July 31, 1967 | 
| File:Blank.svg | Leonard Niederlehner (Acting) | August 1, 1967 – August 20, 1970 | Robert S. McNamara Clark Clifford
 Melvin Laird
 | Lyndon B. Johnson Richard Nixon
 | 
| File:Nixon Contact Sheet WHPO-E1677 (cropped).jpg | J. Fred Buzhardt | August 20, 1970 – January 4, 1974 | Melvin Laird Elliot Richardson
 James R. Schlesinger
 | Richard Nixon | 
| File:Blank.svg | Leonard Niederlehner (Acting) | May 22, 1973 – March 13, 1974 | James R. Schlesinger | 
| File:Martin Richard Hoffmann.jpg | Martin Richard Hoffmann | March 14, 1974 – August 5, 1975 | Richard Nixon Gerald Ford
 | 
| File:Blank.svg | Leonard Niederlehner (Acting) | August 6, 1975 – January 1, 1976 | James R. Schlesinger Donald Rumsfeld
 | Gerald Ford | 
| File:Blank.svg | Richard A. Wiley | January 2, 1976 – January 15, 1977 | Donald Rumsfeld | 
| File:Blank.svg | Deanne C. Siemer | April 28, 1977 – October 15, 1979 | Harold Brown | Jimmy Carter | 
| File:Blank.svg | Leonard Niederlehner (Acting) | October 15, 1979 – February 1, 1980 | 
| File:TogoDWest.jpg | Togo D. West Jr. | February 1, 1980 – January 20, 1981 | 
| File:Blank.svg | Leonard Niederlehner (Acting) | January 20, 1981 – April 1, 1981 | Caspar Weinberger | Ronald Reagan | 
| File:William Howard Taft IV, Deptuty Secretary of Defense, official portrait.JPEG | William Howard Taft IV | April 2, 1981 – May 2, 1984 | 
| File:Portrait of Chapman Beecher Cox.jpg | Chapman B. Cox | May 3, 1984 – December 16, 1985 | 
| File:Portrait of H. Lawrence Garrett III.jpg | Henry L. Garrett III | February 5, 1986 – August 6, 1987 | 
| File:Blank.svg | Leonard Niederlehner (Acting) | August 7, 1987 – October 25, 1987 | 
| File:Portrait of Kathleen A. Buck, Air Force General Counsel DF-SC-87-03100 (6412597).jpg | Kathleen A. Buck | October 26, 1987 – December 30, 1989 | Caspar Weinberger Frank Carlucci
 William Howard Taft IV
 Dick Cheney
 | Ronald Reagan George H. W. Bush
 | 
| File:Portrait of Terrence O'Donnell.jpg | Terrence O'Donnell | October 30, 1989 – March 6, 1992 | Dick Cheney | George H. W. Bush | 
| File:Portrait of C. Paul Beach, Jr.jpg | C. Paul Beach Jr. (Acting) | March 7, 1992 – August 11, 1992 | 
| File:Portrait of David S. Addington, Special Assistant to Secretary of Defense.jpg | David Addington | August 12, 1992 – January 20, 1993 | 
| File:Blank.svg | John H. McNeil (Acting) | January 20, 1993 – May 5, 1993 | Les Aspin | Bill Clinton | 
| File:Portrait of Jamie Gorelick, General Counsel, Department of Defense.jpg | Jamie Gorelick | May 5, 1993 – March 17, 1994 | Lee Aspin William Perry
 | 
| File:Portrait of Stephen W. Preston.jpg | Stephen W. Preston (Acting) | March 28, 1994 – September 28, 1994 | William Perry | 
| File:Judith Miller DoD.jpg | Judith A. Miller | September 29, 1994 – November 7, 1999 | William Perry William Cohen
 | 
| File:Portrait of Douglas A. Dworkin.jpg | Douglas A. Dworkin | November 7, 1999 – June 14, 2000 (Acting) June 14, 2000 – January 19, 2001
 | William Cohen | 
| File:Portrait of William J. Haynes II.jpg | William J. Haynes II | May 24, 2001 – February 26, 2008[2] | Donald Rumsfeld Robert Gates
 | George W. Bush | 
| File:Jeh Johnson official portrait 2011.jpg | Jeh Johnson | February 10, 2009 – December 31, 2012 | Robert Gates Leon Panetta
 | Barack Obama | 
| File:Robert S. Taylor DoD.jpg | Robert S. Taylor (Acting)[3] | January 1, 2013 – October 25, 2013 | Leon Panetta Chuck Hagel
 | 
| File:Stephen W. Preston official photo.jpg | Stephen W. Preston | October 25, 2013 – June 2015 | Chuck Hagel Ashton Carter
 | 
| File:Robert S. Taylor DoD.jpg | Robert S. Taylor (Acting)[3] | June 2015 – June 14, 2016 | Ashton Carter | 
| File:Jennifer M. O'Connor DoD.jpg | Jennifer M. O'Connor | June 14, 2016 – January, 20 2017 | Ashton Carter | 
| File:William S. Castle official photo.jpg | William S. Castle (Acting) | August 2017 – July 2018 | James Mattis | Donald Trump | 
| File:Paul C. Ney Jr. official photo.jpg | Paul C. Ney Jr. | August 20, 2018 – January 20, 2021 | James Mattis Mark Esper
 Christopher C. Miller (acting)
 | 
| File:Beth George.jpg | Beth George (Acting) | January 20, 2021 – August 2, 2021 | David Norquist (acting) Lloyd Austin
 | Joe Biden | 
| File:Caroline Krass, DOD General Counsel.jpg | Caroline Krass | August 2, 2021 – present | Lloyd Austin |