Werner Michael Blumenthal (born January 3, 1926) served as United States Secretary of the Treasury under President Jimmy Carter from 1977-1979.

Born in Berlin, Germany, Blumenthal fled the country with his parents in 1939 shortly before the outbreak of World War II. They went to China, and then to the United States in 1947. He graduated from the University of California at Berkeley in 1951 with a degree in international economics, and later received a Ph.D from Princeton University. Blumenthal alternately worked in the public sector - as Deputy Assistant Secretary of State for Economic Affairs from 1961-1963 and the President's Deputy Special Representative for Trade Negotiations with the rank of Ambassador from 1963 to 1967 - and in the private sector - working for a variety of firms.

Blumenthal served as Secretary of the Treasury from January 23, 1977 to August 4, 1979.

Since 1997, he again lives in Berlin, where he is director of the Jewish Museum Berlin.