Robert J. Dieter (born 1946) is an American lawyer and diplomat who was the United States Ambassador to Belize from 2005 to 2009.

Dieter graduated from the Phillips Academy[1] and then attended Yale University as the roommate of future President George W. Bush.

in 1968[2] and then continued his education at the Vanderbilt University Law School.

[4] In 2003, President Bush appointed Dieter to the board of the Legal Services Corporation.

[5] On October 30, 1971, Dieter married Gwynneth Ann Fletcher Evans in St. James, Long Island, New York.