- Charles M. Dickinson (1901-1903)
- John B. Jackson (1903-1907)
- Horace G. Knowles (1907-1909)
- John B. Jackson (1912-1913)
- Charles J. Vopicka (1913-1918)
- Charles S. Wilson, Interim (1919-1921)
- Charles S. Wilson (1921-1928)
- Henry Wharton Shoemaker (1930-1933)
- Frederick A. Sterling (1934-1936)
- Ray Atherton (1937-1939)
- George H. Earle III (1940-1941)
- Donald R. Heath (1947-1950)
Declared persona non grata by Bulgarian government 19-Jan-1950; U.S. suspends diplomatic relations 21-Feb-1950 - Edward Page, Jr. (1959-1962)
- Eugenie Anderson (1962-1964)
- Nathaniel Davis (1965-1966)
- John M. McSweeney (1966-1970)
- Horace G. Torbert, Jr. (1970-1973)
- Martin F. Herz (1974-1977)
- Raymond L. Garthoff (1977-1979)
- Jack R. Perry (1979-1981)
- Robert L. Barry (1981-1984)
- Melvin Levitsky (1984-1987)
- Sol Polansky (1987-1990)
- Kenneth Hill (1990-1993)
- William D. Montgomery (1993-1996)
- Avis T. Bohlen (1996-1999)
- Richard M. Miles (1999-2002)
- W. Pardew (2002-2005)
- John R. Beyrle (2005-2008)
- Nancy E. McEldowney (2008-2009)
- James B. Warlick, Jr. (2010-2012)
- Marcie B. Ries (2012 – 2015)
- Eric Rubin (2016 – 2019)
- Herro Mustafa (2019 – 2023)