It was originally Harvard's Graduate School of Public Administration, which had been founded in 1936 with a gift from Lucius N. Littauer, and drew its faculty from the existing government and economics departments. In the 1960s, with encouragement from Richard Neustadt, the school expanded to research in public policy, brought in more economics and analytic work to what had been more of a management study, and established a two year "Master in Public Policy Program".
Also in the 1960s, the Institute of Politics (IOP) was established as a memorial to John F. Kennedy.
The various programs were brought together in a single school in 1978.
As of 2003, the school has over 100 faculty and over 800 students. Its alumni include Bill O'Reilly and Colombian president Álvaro Uribe Vélez.