Timothy E. Wirth (born September 22, 1939) is a former United States Senator from Colorado. Wirth, a Democrat, was a member of the House from 1975 to 1987 and was elected to the Senate in 1986, serving one term there before stepping down. He was Under Secretary of State for Global Affairs during the Clinton Administration. In the State Department, he worked with Vice President Al Gore on global environmental and population issues, supporting the administration's views on global warming. A supporter of the proposed Kyoto Protocol, Wirth announced the U.S.'s commitment to legally binding limits on greenhouse gas emissions. Since 1998 he has served as the president of the United Nations Foundation.
Wirth is a graduate of Phillips Exeter Academy and Harvard University and holds a PhD from Stanford University. He has also served as a member of the Harvard Board of Overseers. Wirth is married to Wren Winslow Wirth, the President of the Winslow Foundation; together they have two children, Christopher and Kelsey Wirth. Their daughter, Kelsey Wirth, is the co-founder of the orthodontic production company Align Technology, makers of Invisalign. Their son, Chris Wirth, is founder of Liberty Puzzles, the largest American laser-cut jigsaw puzzle company, based in Boulder, Colorado. His nephew, Peter Wirth, was elected in 2004 to the New Mexico State Legislature. His brother, the late John Wirth, was a professor at Stanford University.
Wirth began his political career as a White House Fellow under President Lyndon Johnson and was Deputy Assistant Secretary for Education in the Nixon Administration. In 1970, Wirth returned to his home state and ran successfully for the U.S. House of Representatives in 1974, unseating incumbent Republican Donald G. Brotzman by a 52% to 48% margin. He represented Boulder and the Denver suburbs in Congress from 1975-1987. As a first term Congressman, Wirth organized the “Freshman Revolt” in 1975 unseating a handful of "old bull" committee chairmen, and encouraging others to be more inclusive. Wirth had a number of difficult reelections during his 12 years in Congress, and raised large sums of money to get reelected. With colleagues Norman Mineta, Leon Panetta and Dick Gephardt, he was part of “The Gang of Four” on the House Budget Committee challenging the budget process with bipartisan budget ideas, and developing a high technology and alternative budget in 1982. As Chair of the Telecommunications Subcommittee, he was the lead legislator in bringing competition to the video and telephone industries. Wirth also authored the Indian Peaks Wilderness Act of 1978.