Chief of Staff

American  

noun

1. the senior officer of the U.S. Army or Air Force, a member of the Joint Chiefs of Staff, responsible to the secretary of a service branch.

2. (lowercase) the senior or principal staff officer in a brigade or division or higher unit in the U.S. Army or Marine Corps, in a numbered unit in the U.S. Air Force, or in a unit in the U.S. Navy commanded by a rear admiral or one of higher rank.

3. (lowercase) the senior officer in command of a general staff, especially that of the military forces of a nation.

4. (lowercase) the head of any staff.

   the chief of staff for the First Lady.

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Chief of Staff British  

noun

1. the senior staff officer under the commander of a major military formation or organization

2. the senior officer of each service of the armed forces

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Etymology

Origin of Chief of Staff

First recorded in 1880–85

Example Sentences

And the lack of churn has also been credited to White House Chief of Staff Susie Wiles, who by most accounts has enforced significant restraint from a famously chaotic leader.

From Slate • Apr. 3, 2026

White House Chief of Staff Susie Wiles has been diagnosed with breast cancer and will continue in her role as she undergoes treatment.

From BBC • Mar. 16, 2026

Twelve candidates, including Price’s Deputy Chief of Staff Jose Ugarte, have entered the race to represent District 9 after he terms out.

From Los Angeles Times • Feb. 8, 2026

And in an interview with Vanity Fair late last year, White House Chief of Staff Susie Wiles said that “it is categorically false, will not happen.”

From Salon • Jan. 26, 2026

The Interim Committee met with its scientific panel for the first time on May 31 at the Pentagon, with Groves and Army Chief of Staff George C. Marshall in attendance.

From "Big Science" by Michael Hiltzik