Harry Mason Reid (; born December 2, 1939) is a retired American attorney and politician who served as a United States Senator from Nevada from 1987 to 2017. He led the Senate's Democratic Conference from 2005 to 2017 and was the Senate Majority Leader from 2007 to 2015.
Reid began his public career as the city attorney for Henderson, Nevada before winning election to the Nevada Assembly in 1968. Reid's former boxing coach, Mike O'Callaghan, chose Reid as his running mate in the 1970 Nevada gubernatorial election, and Reid served as Lieutenant Governor of Nevada from 1971 to 1975. After being defeated in races for the United States Senate and the position of mayor of Las Vegas, Reid served as chairman of the Nevada Gaming Commission from 1977 to 1981. From 1983 to 1987, Reid represented Nevada's 1st district in the United States House of Representatives.
Reid won election to the United States Senate in 1986 and served in the Senate from 1987 to 2017. He served as the Senate Democratic Whip from 1999 to 2005 before succeeding Tom Daschle as Senate Minority Leader. The Democrats won control of the Senate after the 2006 United States Senate elections, and Reid became the Senate Majority Leader in 2007. He held that position for the last two years of George W. Bush's presidency and the first six years of Barack Obama's presidency. As Majority Leader, Reid helped pass major legislation such as the Patient Protection and Affordable Care Act, the Dodd–Frank Act, and the American Recovery and Reinvestment Act of 2009. Republicans took control of the Senate following the 2014 United States Senate elections, and Reid served as Senate Minority Leader from 2015 to his retirement in 2017.
Reid was succeeded as the Senate Democratic leader by Chuck Schumer, whose leadership bid had been endorsed by Reid. Along with Alben W. Barkley and Mike Mansfield, Reid is one of only three senators to serve at least eight years as majority leader.
He is also known as Harry Mason Reid.