Daniel Ellsberg (born April 7, 1931) precipitated a national uproar in 1971 when he released the Pentagon Papers, the US military's account of activities in Vietnam, to The New York Times.

A Vietnam veteran and a senior research associate at the Massachusetts Institute of Technology's Center for International Studies, Ellsberg helped to compile the Pentagon Papers while working in the United States Department of Defense.

Initially, he supported the war effort, but later turned against it. His release of the Pentagon Papers succeeded in eroding public support for the war.