John Francis Hillen III[1][2] (born February 3, 1966) is an American business executive and diplomat who served as the Assistant Secretary of State for Political-Military Affairs from 2005 to 2007.

[3] Hillen served as the CEO and a member of the board of EverWatch Corporation, which was acquired by Booz Allen Hamilton in October 2022.

[4] In April 2015 Hillen was made the inaugural inductee into the Duke University Army ROTC Hall of Fame.

He was featured in Douglas Macgregor's military memoir Warriors Rage: The Great Tank Battle of the 73 Easting.

Hillen is the founder of the GovCon Center at George Mason University and was a columnist for Washington Technology magazine and Forbes.

Prior to his appointment in the Bush administration, he was the head of the defense and intelligence business at American Management Systems.

[9] In 2020, Hillen was inducted into the Army Reserve Officers’ Training Corps Hall of Fame, which honors ROTC graduates who distinguished themselves in their military or civilian pursuits.

[12] From 2013-2019, Hillen served as the executive-in-residence and professor of practice in the School of Business at George Mason University Archived 2018-10-23 at the Wayback Machine.