List of ambassadors of the United States to Canada
This is a list of ambassadors of the United States to Canada. The ambassador is the head of the Embassy of the United States in Ottawa.
Prior to 1943, the head of the U.S. diplomatic mission to Canada bore the title of Envoy Extraordinary and Minister Plenipotentiary. The U.S. mission to Canada was upgraded from legation to embassy status in June 1943, and Ray Atherton was the first chief of mission to hold ambassadorial rank.
| # | Ambassador | Picture | Took office | Left office | President |
| 1 | William Phillips | June 1, 1927 | December 14, 1929 | Calvin Coolidge, Herbert Hoover | |
| 2 | Hanford MacNider | August 29, 1930 | August 15, 1932 | Herbert Hoover | |
| 3 | Warren Delano Robbins | May 16, 1933 | March 28, 1935 | Franklin D. Roosevelt | |
| 4 | Norman Armour | August 7, 1935 | January 15, 1939 | Franklin D. Roosevelt | |
| 5 | Daniel Calhoun Roper | May 19, 1939 | August 20, 1939 | Franklin D. Roosevelt | |
| 6 | James H. R. Cromwell | January 24, 1940 | May 16, 1940 | Franklin D. Roosevelt | |
| 7 | Jay Pierrepont Moffat | June 13, 1940 | January 24, 1943 | Franklin D. Roosevelt | |
| 8 | Ray Atherton | August 3, 1943 | August 30, 1948 | Franklin D. Roosevelt Harry S. Truman | |
| 9 | Laurence Steinhardt | November 1, 1949 | March 28, 1950 | Harry S. Truman | |
| 10 | Stanley Woodward | June 22, 1950 | January 14, 1953 | Harry S. Truman | |
| 11 | R. Douglas Stuart | July 15, 1953 | May 4, 1956 | Dwight D. Eisenhower | |
| 12 | Livingston T. Merchant | May 23, 1956 | November 6, 1958 | Dwight D. Eisenhower | |
| 13 | Richard B. Wigglesworth | December 15, 1958 | October 19, 1960 | Dwight D. Eisenhower | |
| 14 | Livingston T. Merchant | March 15, 1961 | May 26, 1962 | John F. Kennedy | |
| 15 | William Walton Butterworth | December 11, 1962 | September 10, 1968 | John F. Kennedy, Lyndon B. Johnson | |
| 16 | Harold F. Linder | September 10, 1968 | July 9, 1969 | Lyndon B. Johnson, Richard M. Nixon | |
| 17 | Adolph W. Schmidt | September 11, 1969 | January 29, 1974 | Richard M. Nixon | |
| 18 | William J. Porter | March 13, 1974 | December 16, 1975 | Richard M. Nixon, Gerald R. Ford | |
| 19 | Thomas O. Enders | February 17, 1976 | December 14, 1979 | Gerald R. Ford, Jimmy Carter | |
| 20 | Kenneth M. Curtis | October 5, 1979 | January 20, 1981 | Jimmy Carter | |
| 21 | Paul H. Robinson, Jr. | July 15, 1981 | September 9, 1985 | Ronald Reagan | |
| 22 | Thomas M. T. Niles | September 10, 1985 | June 28, 1989 | Ronald Reagan, George H. W. Bush | |
| 23 | Edward N. Ney | June 30, 1989 | June 20, 1992 | George H. W. Bush | |
| 24 | Peter Teeley | July 3, 1992 | February 28, 1993 | George H. W. Bush, Bill Clinton | |
| 25 | James Blanchard | August 19, 1993 | March 15, 1996 | Bill Clinton | |
| 26 | Gordon Giffin | September 17, 1997 | April 10, 2001 | Bill Clinton, George W. Bush | |
| 27 | Paul Cellucci | April 17, 2001 | March 18, 2005 | George W. Bush | |
| 28 | David Wilkins | June 29, 2005 | January 20, 2009 | George W. Bush | |
| 29 | David Jacobson | October 2, 2009 | July 15, 2013 | Barack Obama | |
| 30 | Bruce Heyman | March 26, 2014 | January 20, 2017 | Barack Obama | |
| 31 | Kelly Craft | October 23, 2017 | August 23, 2019 | Donald Trump | |
| 32 | Richard M. Mills Jr. | August 23, 2019 | present | Donald Trump |
On July 31, 2019, Kelly Craft was confirmed by the U.S. Senate as the new United States Ambassador to the United Nations. Aldona Wos, a retired physician and Republican donor from North Carolina, has been nominated as the next ambassador to Canada.