John Sidney McCain III (born August 29, 1936) is the senior United States Senator from Arizona and presumptive Republican Party nominee for President of the United States in the upcoming 2008 election.

McCain graduated from the United States Naval Academy in 1958 and became a naval aviator, flying attack aircraft from carriers. During the Vietnam War, he nearly lost his life in the 1967 USS Forrestal fire. Later that year while on a bombing mission over North Vietnam, he was shot down, badly injured, and captured as a prisoner of war by the North Vietnamese. He spent five and a half years as a prisoner of war, experiencing episodes of torture.

McCain retired from the Navy in 1981 and was elected to the U.S. House of Representatives from Arizona in 1982. After serving two terms, he was elected to the U.S. Senate in 1986, winning re-election in 1992, 1998, and 2004. While generally adhering to conservative principles, McCain established a reputation as a political maverick for disagreeing with his party on several key issues. Surviving the Keating Five scandal of the 1980s, he made campaign finance reform one of his signature concerns, eventually co-sponsoring the Bipartisan Campaign Reform Act in 2002.

McCain lost the Republican nomination in the 2000 presidential election to George W. Bush. He ran again for Republican presidential nomination in 2008 and gained enough delegates to become the presumptive nominee on March 4, 2008.