The 2010 United States Senate elections were held on November 2, 2010, from among the United States Senate's 100 seats. A special election was held on January 19, 2010, for a mid-term vacancy in Massachusetts. Thirty-four of the November elections were for six-year terms to the Senate's Class 3, while other three were special elections to finish incomplete terms. Those 37 November elections featured 19 incumbent Democrats and 18 incumbent Republicans.

The 2008 United States Senate elections were held on November 4, 2008, with 35 of the 100 seats in the Senate being contested. Thirty-three seats were up for regular elections; the winners were eligible to serve six-year terms from January 3, 2009, to January 3, 2015, as members of Class 2. There were also two special elections, the winners of those seats would finish the terms that ended on January 3, 2013. The presidential election, which was won by Democrat Barack Obama, elections for all House of Representatives seats; elections for several gubernatorial elections; and many state and local elections occurred on the same date.