James Henry Roberts Cromwell (June 4, 1896 – March 19, 1990) was an American diplomat, candidate for the United States Senate, author, and one-time husband of Doris Duke, "the richest girl in the world".

He was born on June 4, 1896, in Manhattan, the son of Lucretia Bishop "Eva" Roberts and Oliver Eaton Cromwell.

He published books to present his economic ideas and advocated tighter control of the Federal Reserve.

[4] After bitter and protracted legal proceedings Cromwell and Duke divorced on December 21, 1943.

[1] Cromwell died in the Marin Terrace retirement home in Mill Valley, California, at the age of 93.