The 2010 United States Senate special election in Delaware took place on November 2, 2010, concurrently with elections to the United States Senate in other states, as well as elections to the United States House of Representatives and various state and local elections. It was a special election to fill Delaware's Class II Senate seat, then held by Democrat Ted Kaufman, an appointee. The seat had been previously held by the state's longest-serving senator, Democrat Joe Biden, who vacated it when he became Vice President of the United States in 2009.

Edward Emmett Kaufman is a retired American politician and businessman who served as a United States senator from Delaware from 2009 to 2010. He chaired the Congressional Oversight Panel for the Oversight of the Troubled Asset Relief Program; he was the second and final person to hold the position, succeeding Elizabeth Warren. Kaufman is a member of the Democratic Party and key ally of President Joe Biden.