Jordan Gillis

Jordan Gillis
Official portrait, 2020
Assistant Secretary of the Army for Installations, Energy and Environment
Assumed office
October 6, 2025
PresidentDonald Trump
Preceded byRachel Jacobson
Assistant Secretary of Defense for Sustainment
In office
March 30, 2020 – January 20, 2021
PresidentDonald Trump
Preceded byRobert H. McMahon
Succeeded byChristopher Lowman
Personal details
EducationDuke University (BA)
Emory University (MBA)
Military service
AllegianceUnited States
Branch/serviceUnited States Army
RankMajor
Awards

William Jordan Gillis is an American government official who is serving as the Assistant Secretary of the Army for Installations, Energy and Environment. He had previously served as Assistant Secretary of Defense for Sustainment. He also served as Principal Deputy Assistant Secretary of the Army for Installations, Energy and Environment (ASA IE&E), and earlier as the acting Assistant Secretary of the Army for Installations, Energy and Environment from October 16, 2017, until January 10, 2019.