Robert Orton Work (born January 17, 1953[1]) is an American national security professional who served as the 32nd United States Deputy Secretary of Defense for both the Obama and Trump administrations from 2014 to 2017.

Work's military service began while he was an undergraduate at the University of Illinois, where he was a member of the Naval Reserve Officer Training Corps.

He rose to become base commander of Camp Fuji; the first head of the Marine Corps' Strategic Initiatives Group, a small analytical group that provided advice directly to the Commandant of the Marine Corps; and, in his highest military posting, as Military Assistant and Special Aide to United States Secretary of the Navy Richard Danzig.

He also took a position as an adjunct professor at George Washington University, teaching defense analysis and roles and missions of the armed forces.

Work has criticized former Defense Secretary Donald Rumsfeld for assuming that the United States would always have an advantage in guided weapons and, as such, be able to quickly defeat any foe.

[8] In July 2011, Work called into question the navy's plans for the Lockheed Martin F-35 Lightning II, asking if the numbers or types could be reduced in favor of more unmanned systems.

[14][15] In October 2014, Deputy Secretary Work instructed the Defense Business Board to hire consultants from McKinsey & Company to identify wasteful spending.

[16] Secretary Carter then replaced the board chairman, classified the McKinsey results as secret, and removed the report from public websites.

[17] In December 2019 Work was presented with the Swedish Royal Order of the Polar Star by defense minister Peter Hultqvist.

[21] After retiring as Deputy Defense Secretary, Work in 2018 criticized Google and its employees for, in his view, stepping into a moral hazard for themselves as not continuing Pentagon's artificial intelligence project while helping China's AI technology that could be used against the United States in a conflict.