Biden was born in Scranton, Pennsylvania, and lived there for ten years before moving with his family to Delaware. He became a lawyer in 1969 and was elected to the New Castle County Council in 1970.

Biden attended the Archmere Academy in Claymont where he was a standout halfback/wide receiver on the high school football team; he helped lead a perennially losing team to an undefeated season in his senior year. He played on the baseball team as well. During these years, he participated in an anti-segregation sit-in at a Wilmington theater. Academically, he was an above-average student, was considered a natural leader among the students, and was elected class president during his junior and senior years. He graduated in 1961.

He earned his bachelor's in 1965 from the University of Delaware, with a double major in history and political science, graduating with a class rank of 506 out of 688. His classmates were impressed by his cramming abilities, and he played halfback with the Blue Hens freshman football team. In 1964, while on spring break in the Bahamas, he met and began dating Neilia Hunter, who was from an affluent background in Skaneateles, New York, and attended Syracuse University. He told her that he aimed to become a senator by the age of 30 and then president. He dropped a junior year plan to play for the varsity football team as a defensive back, enabling him to spend more time visiting out of state with her.

On August 27, 1966, Biden married Neilia Hunter (1942–1972), a student at Syracuse University, after overcoming her parents' reluctance for her to wed a Roman Catholic; the ceremony was held in a Catholic church in Skaneateles, New York. They had three children: Joseph R. "Beau" Biden III (1969–2015), Robert Hunter Biden (born 1970), and Naomi Christina "Amy" Biden (1971–1972).

In 1968, Biden earned a Juris Doctor from Syracuse University College of Law, ranked 76th in his class of 85, and was admitted to the Delaware bar in 1969. While in school, he received student draft deferments,[28] and afterward was classified as unavailable for military service due to asthma.

In 1968, Biden clerked at a Wilmington law firm headed by prominent local Republican William Prickett and, he later said, "thought of myself as a Republican".

Biden disliked incumbent Democratic Delaware governor Charles L. Terry's conservative racial politics and supported a more liberal Republican, Russell W. Peterson, who defeated Terry in 1968. Biden was recruited by local Republicans but registered as an Independent because of his distaste for Republican presidential candidate Richard Nixon.

In 1969, Biden practiced law first as a public defender and then at a firm headed by a locally active Democrat who named him to the Democratic Forum, a group trying to reform and revitalize the state party; Biden subsequently reregistered as a Democrat.

Later that year Biden was elected to a county council seat in a usually Republican district of New Castle County, Delaware, running on a liberal platform that included support for public housing in the suburbs. Biden served on the council, while still practicing law, until 1972. He opposed large highway projects that might disrupt Wilmington neighborhoods.

He was first elected to the U.S. Senate in 1972 when he became the sixth-youngest senator in American history.

In 1972, Biden defeated Republican incumbent J. Caleb Boggs to become the junior U.S. senator from Delaware. He was the only Democrat willing to challenge Boggs. His campaign had almost no money, and he was given no chance of winning. Family members managed and staffed the campaign, which relied on meeting voters face-to-face and hand-distributing position papers, an approach made feasible by Delaware's small size.

When the Reagan administration wanted to interpret the 1972 SALT I treaty loosely to allow the development of the Strategic Defense Initiative, Biden argued for strict adherence to the treaty.

On December 18, 1972, a few weeks after the election, Biden's wife and one-year-old daughter Naomi were killed in an automobile accident while Christmas shopping in Hockessin, Delaware.

Biden was sworn in on January 5, 1973, by the secretary of the Senate Francis R. Valeo at the Delaware Division of the Wilmington Medical Center. Present were his sons Beau (whose leg was still in traction from the automobile accident) and Hunter and other family members. At 30, he was the sixth-youngest senator in U.S. history.

In the mid-1970s, Biden was one of the Senate's leading opponents of race-integration busing. His Delaware constituents strongly opposed it, and such opposition nationwide later led his party to mostly abandon school integration policies.

In May 1974, Biden voted to table a proposal containing anti-busing and anti-desegregation clauses but later voted for a modified version containing a qualification that it was not intended to weaken the judiciary's power to enforce the 5th Amendment and 14th Amendment.

Biden credits his second wife, teacher Jill Tracy Jacobs, with the renewal of his interest in politics and life; they met in 1975 on a blind date

In 1975, Biden supported a proposal that would have prevented the Department of Health, Education, and Welfare from cutting federal funds to districts that refused to integrate; he said busing was a "bankrupt idea [violating] the cardinal rule of common sense" and that his opposition would make it easier for other liberals to follow suit.

Biden has received honorary degrees from the University of Scranton (1976).

Biden and Jill Tracy Jacobs were married at the United Nations Chapel in New York on June 17, 1977.

After Congress failed to ratify the SALT II Treaty signed in 1979 by Soviet premier Leonid Brezhnev and President Jimmy Carter, Biden met with Soviet Foreign Minister Andrei Gromyko to communicate American concerns and secured changes that addressed the Senate Foreign Relations Committee's objections.

Biden became a ranking minority member of the Senate Judiciary Committee in 1981.

Biden has received honorary degrees from Saint Joseph's University (LL.D 1981).

In 1984, Biden was a Democratic floor manager for the successful passage of the Comprehensive Crime Control Act; over time, the law's tough-on-crime provisions became controversial and in 2019, Biden called his role in passing the bill a "big mistake".

Biden was a long-time member of the U.S. Senate Committee on the Judiciary. He chaired it from 1987 until 1995 and he served as ranking minority member on it from 1981 until 1987 and again from 1995 until 1997.

Biden formally declared his candidacy for the 1988 Democratic presidential nomination on June 9, 1987.

In February 1988, after several episodes of increasingly severe neck pain, Biden was taken by ambulance to Walter Reed Army Medical Center for surgery to correct a leaking intracranial berry aneurysm. While recuperating he suffered a pulmonary embolism, a serious complication. After a second aneurysm was surgically repaired in May, Biden's recuperation kept him away from the Senate for seven months.

From 1991 to 2008, Biden co-taught a seminar on constitutional law at Widener University School of Law. The seminar often had a waiting list. Biden sometimes flew back from overseas to teach the class.

Biden voted against authorization for the Gulf War in 1991, siding with 45 of the 55 Democratic senators; he said the U.S. was bearing almost all the burden in the anti-Iraq coalition.

Biden became interested in the Yugoslav Wars after hearing about Serbian abuses during the Croatian War of Independence in 1991.

In April 1993, Biden spent a week in the Balkans and held a tense three-hour meeting with Serbian leader Slobodan Milošević. Biden related that he had told Milošević, "I think you're a damn war criminal and you should be tried as one".

In 1993, Biden voted for a provision that deemed homosexuality incompatible with military life, thereby banning gays from serving in the armed forces.

In 1996, Biden voted for the Defense of Marriage Act, which prohibited the federal government from recognizing same-sex marriages, thereby barring individuals in such marriages from equal protection under federal law and allowing states to do the same; in 2015, the act was ruled unconstitutional in Obergefell v. Hodges.

Biden was also a longtime member of the Senate Foreign Relations Committee. He became its ranking minority member in 1997, and chaired it from June 2001 to 2003 and 2007 to 2009.

In 1999, during the Kosovo War, Biden supported the 1999 NATO bombing of the Federal Republic of Yugoslavia. He co-sponsored with John McCain the McCain-Biden Kosovo Resolution, which called on President Clinton to use all necessary force, including ground troops, to confront Milošević over Yugoslav actions toward ethnic Albanians in Kosovo.

Biden has received honorary degrees from Widener University School of Law (2000).

Biden was a strong supporter of the 2001 war in Afghanistan, saying, "Whatever it takes, we should do it." As head of the Senate Foreign Relations Committee, Biden said in 2002 that Saddam Hussein was a threat to national security and there was no option but to "eliminate" that threat.

In October 2002, Biden voted in favor of the Authorization for Use of Military Force Against Iraq, approving the U.S. invasion of Iraq. As chair of the committee, he assembled a series of witnesses to testify in favor of the authorization. They gave testimony grossly misrepresenting the intent, history and status of Saddam and his secular government, which was an avowed enemy of al-Qaida, and touting Iraq's fictional possession of weapons of mass destruction.

Biden has received honorary degrees from Emerson College (2003).

Biden has received honorary degrees from Delaware State University (2003).

Biden has received his alma mater the University of Delaware (LL.D 2004).

Biden has received honorary degrees from Suffolk University Law School (2005).

In November 2006, Biden and Leslie H. Gelb, president emeritus of the Council on Foreign Relations, released a comprehensive strategy to end sectarian violence in Iraq. Rather than continuing the present approach or withdrawing, the plan called for "a third way": federalizing Iraq and giving Kurds, Shiites, and Sunnis "breathing room" in their own regions.

By late 2006, Biden's stance had shifted considerably, and he opposed the troop surge of 2007, saying General David Petraeus was "dead, flat wrong" in believing the surge could work. Biden instead advocated dividing Iraq into a loose federation of three ethnic states.

Biden declared his candidacy for president on January 31, 2007, after having discussed running for months prior. Biden made a formal announcement to Tim Russert on Meet the Press, stating he would "be the best Biden I can be". In January 2006, Delaware newspaper columnist Harry F. Themal wrote that Biden "occupies the sensible center of the Democratic Party". Themal concludes that this is the position Biden desires and that in a campaign "he plans to stress the dangers to the security of the average American, not just from the terrorist threat, but from the lack of health assistance, crime, and energy dependence on unstable parts of the world".

Soon after the election, he was appointed the chairman of president-elect Obama's transition team. During the transition phase of the Obama administration, Biden said he was in daily meetings with Obama and that McCain was still his friend. The U.S. Secret Service codename given to Biden is "Celtic", referencing his Irish roots.

Biden declared his candidacy for president on January 31, 2007, after having discussed running for months prior. Biden made a formal announcement to Tim Russert on Meet the Press, stating he would "be the best Biden I can be." In January 2006, Delaware newspaper columnist Harry F. Themal wrote that Biden "occupies the sensible center of the Democratic Party." Thermal concludes that this is the position Biden desires and that in a campaign "he plans to stress the dangers to the security of the average American, not just from the terrorist threat, but from the lack of health assistance, crime, and energy dependence on unstable parts of the world."

In May 2008, Biden sharply criticized President George W. Bush for a speech to Israel's Knesset in which he compared some Democrats to Western leaders who appeased Hitler before World War II; Biden called the speech "bullshit", "malarkey", and "outrageous". He later apologized for his language.

On November 4, 2008, Biden was elected Vice President of the United States as Obama's running mate.

Also in 2008, Biden shared with fellow senator Richard Lugar the Government of Pakistan's Hilal-i-Pakistan award "in recognition of their consistent support for Pakistan".

In 2008, Biden received Working Mother magazine's Best of Congress Award for "improving the American quality of life through family-friendly work policies".

Biden was the running mate of Democratic presidential nominee Barack Obama and became the first Roman Catholic to serve as vice president of the United States.

At noon on January 20, 2009, Joe Biden became the 47th vice president of the United States, sworn into the office by Supreme Court Justice John Paul Stevens. Biden is the first United States vice president from Delaware and the first Roman Catholic to attain that office.

In May, Biden visited Kosovo and affirmed the U.S. position that its "independence is irreversible".

Confronted with rising unemployment through July 2009, Biden acknowledged that the administration had "misread how bad the economy was" but maintained confidence the stimulus package would create many more jobs once the pace of expenditures picked up.

Biden lost an internal debate to Secretary of State Hillary Clinton about sending 21,000 new troops to Afghanistan, but his skepticism was valued, and in 2009, Biden's views gained more influence as Obama reconsidered his Afghanistan strategy.

In 2009, Kosovo gave Biden the Golden Medal of Freedom, the region's highest award, for his vocal support for its independence in the late 1990s.

Biden has received his other alma mater Syracuse University (LL.D 2009).

Biden has received honorary degrees from Wake Forest University (LL.D 2009).

Biden is an inductee of the Delaware Volunteer Firemen's Association Hall of Fame.

In January 2010, Biden visited Iraq in the midst of turmoil over banned candidates from the upcoming Iraqi parliamentary election resulted in 59 of the several hundred candidates being reinstated by the Iraqi government two days later.

On March 23, 2010, a microphone picked up Biden telling the president that his signing the Patient Protection and Affordable Care Act was "a big fucking deal" during live national news telecasts. White House press secretary Robert Gibbs replied on Twitter, "And yes Mr. Vice President, you're right ...".

On June 11, 2010, Biden represented the United States at the opening ceremony of the World Cup, attended the England v. U.S. game, and visited Egypt, Kenya, and South Africa.

In October 2010, Biden stated that Obama had asked him to remain as his running mate for the 2012 presidential election. With Obama's popularity on the decline, however, in late 2011 White House Chief of Staff William M. Daley conducted some secret polling and focus group research into the idea of Secretary of State Clinton replacing Biden on the ticket. The notion was dropped when the results showed no appreciable improvement for Obama, and White House officials later said that Obama had never entertained the idea.

In October 2010, Biden said Obama had asked him to remain as his running mate for the 2012 presidential election, but with Obama's popularity on the decline, White House Chief of Staff William M. Daley conducted some secret polling and focus group research in late 2011 on the idea of replacing Biden on the ticket with Hillary Clinton.

In December 2010, Biden's advocacy for a middle ground, followed by his negotiations with Senate minority leader Mitch McConnell, were instrumental in producing the administration's compromise tax package that included a temporary extension of the Bush tax cuts.

In foreign policy, Biden supported the NATO-led military intervention in Libya in 2011.

In March 2011, Obama delegated Biden to lead negotiations between Congress and the White House in resolving federal spending levels for the rest of the year and avoiding a government shutdown.

By May 2011, a "Biden panel" with six congressional members was trying to reach a bipartisan deal on raising the U.S. debt ceiling as part of an overall deficit reduction plan.

The U.S. debt ceiling crisis developed over the next few months, but Biden's relationship with McConnell again proved key in breaking a deadlock and bringing about a deal to resolve it, in the form of the Budget Control Act of 2011, signed on August 2, 2011, the same day an unprecedented U.S. default had loomed.

Biden's May 2012 statement that he was "absolutely comfortable" with same-sex marriage gained considerable public attention in comparison to Obama's position, which had been described as "evolving".

In December 2012, Obama named Biden to head the Gun Violence Task Force, created to address the causes of gun violence in the United States in the aftermath of the Sandy Hook Elementary School shooting.

Biden was inaugurated to a second term in the early morning of January 20, 2013, at a small ceremony in his official residence with Justice Sonia Sotomayor presiding (a public ceremony took place on January 21). He continued to be at the forefront as, in the wake of the Sandy Hook Elementary School shooting, the Obama administration put forth executive orders and proposed legislation towards new gun control measures (the legislation failed to pass).

Biden was inaugurated to a second term on January 20, 2013, at a small ceremony at Number One Observatory Circle, his official residence, with Justice Sonia Sotomayor presiding (a public ceremony took place on January 21).

Biden has received honorary degrees from the University of Pennsylvania (LL.D 2013).

Biden favored arming Syria's rebel fighters. As Iraq fell apart during 2014, a renewed attention was paid to the Biden-Gelb Iraqi federalization plan of 2006, with some observers suggesting Biden had been right all along. Biden himself said the U.S. would follow ISIL "to the gates of hell".

Biden has received honorary degrees from the Miami Dade College (2014).

Biden has received honorary degrees from the University of South Carolina (DPA 2014).

In 2015, Speaker of the House John Boehner and Senate majority leader Mitch McConnell invited Israeli prime minister Benjamin Netanyahu to address a joint session of Congress without notifying the Obama administration. This defiance of protocol led Biden and more than 50 congressional Democrats to skip Netanyahu's speech.

On May 30, 2015, Biden's son, Beau Biden, died at age 46 after having battled brain cancer for several years. In a statement, the Vice President's office said, "The entire Biden family is saddened beyond words." The nature and seriousness of the illness had not been previously disclosed to the public, and Biden had quietly reduced his public schedule in order to spend more time with his son. At the time of his death, Beau Biden had been widely seen as the frontrunner to be the Democratic nominee for Governor of Delaware in 2016.

On October 21, speaking from a podium in the Rose Garden with his wife and Obama by his side, Biden announced his decision not to run for president in 2016. In January 2016, Biden affirmed that it was the right decision, but admitted to regretting not running for president "every day".

On December 8, 2015, Biden spoke in Ukraine's parliament in Kyiv in one of his many visits to set U.S. aid and policy stance on Ukraine.

In 2015, Biden pressured the Ukrainian parliament to remove Shokin because the United States, the European Union, and other international organizations considered Shokin corrupt and ineffective, and in particular because Shokin was not assertively investigating Burisma. The withholding of the $1 billion in aid was part of this official policy.

After Obama endorsed Hillary Clinton on June 9, 2016, Biden endorsed her later that day.

In August 2016, Biden visited Serbia, where he met with Serbian President Aleksandar Vučić and expressed his condolences for civilian victims of the bombing campaign during the Kosovo War.

Biden has received honorary degrees from Trinity College (LL.D 2016).

Biden has received honorary degrees from Colby College (LL.D 2017).

Biden has received honorary degrees from Morgan State University (DPS 2017).

The 2020 presidential campaign of Joe Biden began on April 25, 2019, when Biden released a video announcing his candidacy in the 2020 Democratic party presidential primaries. Joe Biden, the former vice president of the United States and a former U.S. senator from Delaware, had been the subject of widespread speculation as a potential 2020 candidate after declining to be a candidate in the 2016 election. As a former vice president, Biden entered the race with very high name recognition. From his campaign announcement until late September, he was generally considered the front runner of the race and led the national primary in most major polls.

In September 2019, it was reported that Trump had pressured Ukrainian president Volodymyr Zelensky to investigate alleged wrongdoing by Biden and his son Hunter Biden. Despite the allegations, as of September 2019, no evidence has been produced of any wrongdoing by the Bidens. The media widely interpreted this pressure to investigate the Bidens as trying to hurt Biden's chances of winning the presidency, resulting in a political scandal and Trump's impeachment by the House of Representatives.

Beginning in 2019, Trump and his allies falsely accused Biden of getting the Ukrainian prosecutor general Viktor Shokin fired because he was supposedly pursuing an investigation into Burisma Holdings, which employed Hunter Biden. Biden was accused of withholding $1 billion in aid from Ukraine in this effort.

When Sanders suspended his campaign on April 8, 2020, Biden became the Democratic Party's presumptive nominee for president.

On April 13, Sanders endorsed Biden in a live-streamed discussion from their homes.

Former President Barack Obama endorsed Biden the next day.

On August 11, Biden announced U.S. Senator Kamala Harris of California as his running mate, making her the first African American and South Asian American vice-presidential nominee on a major-party ticket.

On August 18, 2020, Biden was officially nominated at the 2020 Democratic National Convention as the Democratic Party nominee for president in the 2020 election.

Biden was elected the 46th president of the United States in November 2020.

On November 11, 2020, Biden chose Ron Klain as his White House Chief of Staff. Klain was a Senate aide to Biden in the 1980s, Biden's first chief of staff as Vice President, and chief of staff to Vice President Al Gore.

On November 23, 2020, Biden made his first national security nominations and appointments, nominating Antony Blinken for Secretary of State, Alejandro Mayorkas for Secretary of Homeland Security, Avril Haines for Director of National Intelligence, Jake Sullivan for National Security Advisor, Linda Thomas-Greenfield for United States Ambassador to the United Nations, and former Secretary of State John Kerry for Special Presidential Envoy for Climate.

Also on November 23, General Services Administrator Emily W. Murphy formally recognized Biden as the apparent winner of the 2020 election and authorized the start of a transition process to the Biden administration.

On December 10, 2020, Biden and Harris were jointly named Time Person of the Year.

Biden was inaugurated as the 46th president of the United States on January 20, 2021. At the age of 78, he is the oldest person to have assumed the office. He is the second Catholic president (the other being John F. Kennedy) and the first president whose home state is Delaware.