John Lawrence Sullivan (June 16, 1899 – August 8, 1982) was an American lawyer who served in several positions in the US federal government, including as Secretary of the Navy, the first during the administration of Harry S. Truman.

Sullivan's major contributions to the Navy's future directions include the advent of naval nuclear propulsion.

In 1947, then-Captain Hyman G. Rickover went around his chain-of-command and directly to the Chief of Naval Operations, Fleet Admiral Chester W. Nimitz, by chance also a former submariner, to pitch his ideas for creating a nuclear-powered warship.

"[3][4] In May 1949, Sullivan resigned in protest after the second Secretary of Defense, Louis A. Johnson, canceled the heavy aircraft carrier USS United States (CVA-58).

[6] The house that Sullivan and his wife lived in, constructed in 1932–1933 in Manchester, New Hampshire, was added to the National Register of Historic Places in July 2023.