The 2008 United States presidential election was the 56th quadrennial presidential election, held on November 4, 2008. The Democratic ticket of Barack Obama, the junior senator from Illinois, and Joe Biden, the senior senator from Delaware, defeated the Republican ticket of John McCain, the senior senator from Arizona, and Sarah Palin, the governor of Alaska. Obama became the first African American to be elected to the presidency, as well as being only the third sitting United States senator elected president, joining Warren G. Harding and John F. Kennedy. Meanwhile, this was only the second successful all-senator ticket since the 1960 election and is the only election where both major party nominees were sitting senators. This was the first election since 1952 in which neither the incumbent president nor vice president was on the ballot, as well as the first election since 1928 in which neither ran for the nomination.

The election of the president and the vice president of the United States is an indirect election in which citizens of the United States who are registered to vote in one of the fifty U.S. states or in Washington, D.C., cast ballots not directly for those offices, but instead for members of the Electoral College. These electors then cast direct votes, known as electoral votes, for president, and for vice president. The candidate who receives an absolute majority of electoral votes is then elected to that office. If no candidate receives an absolute majority of the votes for president, the House of Representatives elects the president; likewise if no one receives an absolute majority of the votes for vice president, then the Senate elects the vice president.