Timothy Endicott Wirth (born September 22, 1939, in Santa Fe, New Mexico) is an American politician, diplomat, and environmental advocate. A Democrat, he served as a U.S. Representative from Colorado's 2nd district (1975-1987) and as a U.S. Senator from Colorado (1987-1993). He is known for his work on telecommunications policy and for sponsoring environmental legislation, particularly on global climate change and population stabilization. He later served as Under Secretary of State for Global Affairs (1993-1997). After his government service, he was president of the United Nations Foundation and Better World Fund (1997-2013) and later served as vice chair. He holds degrees from Harvard College, Harvard Graduate School of Education, and Stanford University (Ph.D.), and began his career as a White House Fellow under President Lyndon B. Johnson.