The Republican Party is one of the two major contemporary political parties in the United States, along with the Democratic Party. Founded by anti-slavery expansion activists in 1854, it is often called the Grand Old Party or the GOP, despite being the younger of the two major parties. The party's platform is generally considered right of center in the U.S. political spectrum.

The Republican Party has the second most registered voters as of 2004 with 55 million, encompassing roughly one-third of the electorate. As of mid-2010, Republicans fill a minority of seats in both the United States Senate and the House of Representatives, hold a minority of state governorships, and control a minority of state legislatures.