Chenault, who is of African American heritage, was born in Mineola, New York, the son of a dentist and dental hygienist.

The elder Chenault passed the New York State dental exam with the highest score ever recorded as of January 2014.

Chenault began his career as an associate at the law firm Rogers & Wells (1977–1979) in New York City, and as a consultant for Bain & Company (1979–1981).

[24] In December 2018, it was announced that Chenault would step down from his board roles at IBM and Procter & Gamble on February 13, 2019.

[29][30] On November 15, 2010, Old North Foundation recognized Chenault with its Third Lantern Award for individual commitment and dedication to public service.

[31] Chenault and wife, Kathryn, are founding donors to the Art for Justice Fund, which aims to reduce prison populations and strengthen employment opportunities for those leaving.

[8][33] On February 6, 2017, Chenault was named chair of the advisory council for the Smithsonian's National Museum of African American History and Culture.

[37] In October 2024, it was reported that Chenault is a potential choice for United States Secretary of the Treasury should Harris win in the upcoming presidential election.