The 2012 United States Senate elections were held on November 6, 2012, with 33 of the 100 seats in the Senate, all Class 1 seats, being contested in regular elections whose winners would serve six-year terms beginning January 3, 2013, with the 113th Congress. Democrats had 21 seats up for election, plus 1 Independent and 1 Independent Democrat, while the Republicans had only 10 seats up for election. The presidential election, elections to the House of Representatives, elections for governors in 14 states and territories, and many state and local elections were also held on the same day.

The 113th United States Congress was a meeting of the legislative branch of the United States federal government, from January 3, 2013, to January 3, 2015, during the fifth and sixth years of Barack Obama's presidency. It was composed of the United States Senate and the United States House of Representatives based on the results of the 2012 Senate elections and the 2012 House elections. The seats in the House were apportioned based on the 2010 United States census. It first met in Washington, D.C., on January 3, 2013, and it ended on January 3, 2015. Senators elected to regular terms in 2008 were in the last two years of those terms during this Congress.