Eleanor Martha Hadley (July 17, 1916 – June 1, 2007) was an American economist and policymaker. Because of her relatively rare research specialization in Japanese economics, during World War II Hadley was recruited first into OSS and then the State Department to support the United States' war effort while she was a doctoral candidate in economics at Radcliffe College. Hadley helped draft the United States' plans for dissolving zaibatsu business conglomerates as part of a planned effort to democratize Japan after the war, and she participated in implementing this economic deconcentration program when the postwar occupation brought her to Japan to work for SCAP as an economist.