List of ambassadors of the United States to Singapore
The following individuals served as United States Ambassador to the Republic of Singapore.
| No. | Name | Took office | Left office | President |
| 1 | Richard H. Donald Chargé d'Affaires, a.i. | April 4, 1966 | September 1966 | Lyndon B. Johnson |
| 2 | Francis Joseph Galbraith | 1966 | 1969 | Lyndon B. Johnson |
| 3 | Charles T. Cross | 1969 | 1972 | Richard Nixon |
| 4 | Edwin M. Cronk | 1972 | 1975 | Richard Nixon Gerald Ford |
| 5 | John H. Holdridge | 1975 | 1978 | Gerald Ford Jimmy Carter |
| 6 | Richard F. Kneip | May 26, 1978 | September 25, 1980 | Jimmy Carter |
| 7 | Harry E. T. Thayer | 1980 | 1985 | Jimmy Carter Ronald Reagan |
| 8 | J. Stapleton Roy | 1984 | 1986 | Ronald Reagan |
| 9 | Daryl Arnold | April 28, 1987 | July 8, 1989 | Ronald Reagan George H. W. Bush |
| 10 | Robert D. Orr | July 14, 1989 | September 12, 1992 | George H. W. Bush |
| 11 | Jon Huntsman Jr. | September 22, 1992 | June 15, 1993 | George H. W. Bush Bill Clinton |
| 12 | Ralph L. Boyce Chargé d'Affaires, a.i. | June 1993 | September 1994 | Bill Clinton |
| 13 | Timothy Chorba | 1994 | 1997 | Bill Clinton |
| 14 | Steven J. Green | November 18, 1997 | March 1, 2001 | Bill Clinton George W. Bush |
| 15 | Frank Lavin | September 10, 2001 | October 11, 2005 | George W. Bush |
| 16 | Patricia L. Herbold | November 7, 2005 | January 20, 2009 | George W. Bush |
| 17 | David I. Adelman | April 29, 2010 | September 4, 2013 | Barack Obama |
| 18 | Kirk Wagar | September 25, 2013 | January 20, 2017 | Barack Obama |
| 19 | Stephanie Syptak-Ramnath Chargé d'Affaires, a.i. | January 20, 2017 | July 26, 2019 | Donald Trump |
| 20 | Rafik Mansour Chargé d'Affaires, a.i. | August 1, 2019 | Present | Donald Trump |
- The position of ambassador to Singapore has been vacant since Wagar resigned in January 2017, as is customary for ambassadors when a new administration takes office. Stephanie Syptak-Ramnath took over the handling of the embassy, serving as chargé d'affaires, ad interim and acting United States ambassador to Singapore. Former Deputy US National Security Adviser K. T. McFarland was nominated as the ambassadorship to Singapore though withdrew her nomination in February 2018; the position requires confirmation by the US Senate. Rafik Mansour takes over the handling of the embassy as the new Chargé d'Affaires on July 30 while the ambassadorship remains vacant. President Trump nominated Barbera Hale Thornhill, president of Impact Design, a business-focused interior design firm in Los Angeles, California, as ambassador on 19 September 2019.