• 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)