Bernard Sanders (born September 8, 1941) is an American politician and activist who is the senior United States senator from Vermont. Sanders is the longest-serving independent in U.S. congressional history, but maintains a close relationship with the Democratic Party, having caucused with House and Senate Democrats for most of his congressional career and sought the party's presidential nomination in 2016 and 2020.

Born into a working-class Jewish family and raised in the Brooklyn borough of New York City, Sanders attended Brooklyn College before graduating from the University of Chicago in 1964. While a student, he was a protest organizer for the Congress of Racial Equality (CORE) and the Student Nonviolent Coordinating Committee (SNCC) during the civil rights movement. After settling in Vermont in 1968, he ran unsuccessful third-party political campaigns in the early to mid-1970s. He was elected mayor of Burlington in 1981 as an independent and was reelected three times. He won election to the U.S. House of Representatives in 1990, representing Vermont's at-large congressional district. In 1991, Sanders and five other House members co-founded the Congressional Progressive Caucus, which now has more than 100 members. He was a U.S. representative for 16 years before being elected to the U.S. Senate in 2006, becoming the first non-Republican elected to Vermont's Class 1 seat since Whig Solomon Foot was elected in 1850. Sanders was reelected to the Senate in 2012, 2018, and 2024. He chaired the Senate Veterans' Affairs Committee from 2013 to 2015 and the Senate Budget Committee from 2021 to 2023. In January 2023, he became chair of the Senate Health, Education, Labor and Pensions Committee and the senior senator and dean of the Vermont congressional delegation upon Patrick Leahy's retirement from the Senate.

Sanders was a major candidate for the Democratic presidential nomination in 2016 and 2020, finishing in second place both times against Hillary Clinton and Joe Biden, respectively. Despite initially low expectations, his 2016 campaign generated significant grassroots enthusiasm and funding from small-dollar donors, carrying him to victory in 23 primaries and caucuses. In 2020, his strong showing in early primaries and caucuses made him the front-runner in a historically large field of Democratic candidates. He supported both Clinton and Biden in their respective general election campaigns against Donald Trump. After the 2020 primaries, he became a close ally of Biden.

Sanders is credited with influencing a leftward shift in the Democratic Party after his 2016 presidential campaign. An advocate of progressive policies, he is known for his opposition to neoliberalism and support for workers' self-management. On domestic policy, he supports labor rights, universal and single-payer healthcare, paid parental leave, tuition-free tertiary education, a Green New Deal to create jobs addressing climate change, and worker control of production through cooperatives, unions, and democratic public enterprises. On foreign policy, he supports reducing military spending, pursuing more diplomacy and international cooperation, and putting greater emphasis on labor rights and environmental concerns when negotiating international trade agreements. Sanders supports workplace democracy and has praised elements of the Nordic model. Some have compared and contrasted his politics to left-wing populism and the New Deal policies of President Franklin D. Roosevelt.