William Harding Jackson (II) (March 25, 1901 – September 28, 1971) was a U.S. civilian administrator, New York lawyer, and investment banker who served as Deputy Director of the Central Intelligence Agency. Jackson also served briefly under President Dwight D. Eisenhower as United States National Security Advisor in 1956 while in his role as Special Assistant for National Security Affairs from 1956 to 1957.