Joseph Robinette Biden Jr. ( ROB-in-it BY-dən; born November 20, 1942) is an American politician who has been the 46th and current president of the United States since 2021. A member of the Democratic Party, he served as the 47th vice president from 2009 to 2017 under President Barack Obama and represented Delaware in the U.S. Senate from 1973 to 2009.

Born in Scranton, Pennsylvania, Biden moved with his family to Delaware in 1953. He received a Bachelor of Arts from the University of Delaware in 1965 and a Juris Doctor from Syracuse University in 1968. He was elected to the New Castle County Council in 1970 and the U.S. Senate in 1972. As a senator, Biden drafted and led the effort to pass the Violent Crime Control and Law Enforcement Act and the Violence Against Women Act. He also oversaw six U.S. Supreme Court confirmation hearings, including the contentious hearings for Robert Bork and Clarence Thomas. Biden ran unsuccessfully for the 1988 and 2008 Democratic presidential nominations. In 2008, Obama chose Biden as his running mate, and he was a close counselor to Obama during his two terms as vice president. In the 2020 presidential election, the Democratic Party nominated Biden for president. He selected Kamala Harris as his running mate, and they defeated Republican incumbents Donald Trump and Mike Pence. He became the oldest president in U.S. history and the first to serve with a female vice president.

As president, Biden signed the American Rescue Plan Act in response to the COVID-19 pandemic and subsequent recession. He signed bipartisan bills on infrastructure and manufacturing. He proposed the Build Back Better Act, which failed in Congress, but aspects of which were incorporated into the Inflation Reduction Act that he signed into law in 2022. Biden appointed Ketanji Brown Jackson to the Supreme Court. He worked with congressional Republicans to resolve the 2023 debt-ceiling crisis by negotiating a deal to raise the debt ceiling. In his foreign policy, Biden restored America's membership in the Paris Agreement. He oversaw the complete withdrawal of U.S. troops from Afghanistan that ended the war in Afghanistan, leading to the collapse of the Afghan government and the Taliban seizing control. He responded to the Russian invasion of Ukraine by imposing sanctions on Russia and authorizing civilian and military aid to Ukraine. During the Israel–Hamas war, Biden condemned the actions of Hamas as terrorism and sent military aid to Israel, as well as limited humanitarian aid to the Gaza Strip.

In April 2023, Biden announced his reelection campaign and, after the Democratic primaries, became the party's presumptive nominee in the 2024 presidential election. Concerns about Biden's age and health persisted throughout his term, with renewed scrutiny after his performance during the first presidential debate on June 27. On July 21, he withdrew his candidacy, becoming the first U.S. president to decline to seek reelection after securing enough delegates to win renomination. Biden endorsed Vice President Harris to be the Democratic presidential nominee. Harris won the nomination but lost the general election to Trump.