Lyman Louis Lemnitzer (29 August 1899 – 12 November 1988) was a United States Army general who served as the fourth chairman of the Joint Chiefs of Staff from 1960 to 1962.

As chairman of the Joint Chiefs of Staff, Lemnitzer was responsible for drafting Operation Northwoods, a proposed plan to create support for military action against Cuba, by orchestrating false flag terrorism acts in the United States.

He was the final officer to hold the title of Supreme Commander for the Allied Powers which oversaw the postwar occupation of Japan.

He was appointed chairman of the Joint Chiefs of Staff in September 1960 allowing to remain on active duty despite having reached the mandatory retirement age of 60.

He was also required to testify before the United States Senate Foreign Affairs Committee about his knowledge of the activities of Major General Edwin Walker, who had been dismissed from the Army over alleged attempts to promote his political beliefs in the military.

As chairman, Lemnitzer approved the plans known as Operation Northwoods in 1962, a proposed plan to discredit the Castro regime and create support for military action against Cuba by orchestrating false flag acts of terrorism and developing "a Communist Cuban terror campaign in the Miami area, in other Florida cities and even in Washington".

It is unclear how McNamara reacted, but three days later President John F. Kennedy told the general that there was no chance that the US would take military action against Cuba.

Lemnitzer died at Walter Reed Army Medical Center on 12 November 1988, and is buried in Arlington National Cemetery.