| Name | Year appointed | President(s) served under | |
|---|---|---|---|
| Henry Knox | 1789 | George Washington | |
| Timothy Pickering | 1795 | Washington | |
| James McHenry | 1796 | Washington, John Adams | |
| Samuel Dexter | 1800 | John Adams | |
| Henry Dearborn | 1801-1809 | Thomas Jefferson | |
| William Eustis | 1809-1813 | James Madison | |
| John Armstrong, Jr | 1813-1814 | Madison | |
| James Monroe | 1814-1815 | Madison | |
| William Harris Crawford | 1815-1816 | Madison | |
| John C. Calhoun | 1817-1825 | James Monroe | |
| James Barbour | 1825-1828 | John Quincy Adams | |
| Peter Buell Porter | 1828-1829 | John Quincy Adams | |
| John Henry Eaton | 1829-1831 | Andrew Jackson | |
| Lewis Cass | 1831-1836 | Jackson | |
| Joel Roberts Poinsett | 1837-1841 | Martin Van Buren | |
| John Bell | 1841 | William Henry Harrison, John Tyler | |
| John C. Spencer | 1841-1843 | Tyler | |
| James Madison Porter | 1843-1844 | Tyler | |
| William Wilkins | 1844-1845 | Tyler | |
| William L. Marcy | 1845-1849 | James Polk | |
| George Walker Crawford | 1849-1850 | Zachary Taylor | |
| Charles Magill Conrad | 1850-1853 | Millard Fillmore | |
| Jefferson Davis | 1853-1857 | Franklin Pierce | |
| John Buchanan Floyd | 1857-1860 | James Buchanan | |
| Joseph Holt | 1861 | Buchanan | |
| Simon Cameron | 1861-1862 | Abraham Lincoln | |
| Edwin M. Stanton | 1862-1868 | Lincoln, Andrew Johnson | |
| John M. Schofield | 1868-1869 | Johnson | |
| John Aaron Rawlins | 1869 | Ulysses Simpson Grant | |
| William Tecumseh Sherman | 1869 | Grant | |
| William W. Belknap | 1869-1876 | Grant | |
| Alphonso Taft | 1876 | Grant | |
| J. Donald Cameron | 1876-1877 | Grant | |
| George Washington McCrary | 1877-1879 | Rutherford B. Hayes | |
| Alexander Ramsey | 1879-1881 | Hayes | |
| Robert Todd Lincoln | 1881-1885 | Chester Alan Arthur | |
| William C. Endicott | 1885-1889 | Grover Cleveland | |
| Redfield Proctor | 1889-1891 | Benjamin Harrison | |
| Stephen B. Elkins | 1891-1893 | Harrison | |
| Daniel Scott Lamont | 1893-1897 | Cleveland (2nd term) | |
| Russell A. Alger | 1897-1899 | William McKinley | |
| Elihu Root | 1899-1904 | McKinley, Theodore Roosevelt | |
| William Howard Taft | 1904-1908 | Theodore Roosevelt | |
| Luke Edward Wright | 1908-1909 | Theodore Roosevelt | |
| Jacob M. Dickinson | 1909-1911 | William Howard Taft | |
| Henry L. Stimson | 1911-1913 | Taft | |
| Lindley M. Garrison | 1913-1916 | Woodrow Wilson | |
| Newton D. Baker | 1916-1921 | Wilson | |
| John W. Weeks | 1921-1925 | Warren G. Harding, Calvin Coolidge | |
| Dwight F. Davis | 1925-1929 | Coolidge | |
| James W. Good | 1929 | Herbert Hoover | |
| Patrick J. Hurley | 1929-1933 | Hoover | |
| George H. Dern | 1933-1936 | Franklin Delano Roosevelt | |
| Harry H. Woodring | 1936-1940 | FDR | |
| Henry L. Stimson | 1940-1945 | FDR, Harry S. Truman | |
| Robert P. Patterson | 1945-1947 | Truman | |
| Kenneth C. Royall | 1947 | Truman |