The following are lists of candidates in the 2008 United States presidential election. Candidates who are not on any state ballots, withdrew from the race, suspended their presidential campaign, or failed to earn their party's nomination are listed separately.

Party nominees

All candidates in the table below are on the ballot in multiple states. Those who are on the ballot in enough states to win a majority in the U.S. Electoral College are marked in bold. Candidates who are on the ballot in no more than one state are listed in the next section.

Ron Paul is on the ballot in Louisiana with Barry Goldwater, Jr. on the Louisiana Taxpayers Party line and in Montana with Michael Peroutka on the Montana Constitution Party line, even though the latter is associated with the national Constitution Party. Paul is no longer running for president and has asked to be removed from the ballot. On 10 September 2008, Paul confirmed his open endorsement for Baldwin, Barr, McKinney, and Nader at a press conference in Washington D.C.Ron Paul urges voters to skip McCain, Obama, CNNPolitics.com. Retrieved on 2008-09-10. He later appeared on CNN's The Situation Room with Wolf Blitzer with Nader where they presented and briefly laid out the four principles that these candidates had agreed on as the most important key issues of the presidential race.

Ballot access

The two major parties in the United States, the Democratic Party and the Republican Party, have ballot access in all 50 U.S. states and the District of Columbia.

Each state sets its own requirements for candidates to gain ballot access. In some cases it is easier for party nominees to gain ballot access than for independent candidates, so Ralph Nader's independent campaign is associated with parties (pre-existing or newly formed) in some states: PF is the Peace and Freedom Party, NLP is the Natural Law Party, IEP is the Independent-Ecology Party, and IP is the Independent Party. In Kansas, Chuck Baldwin's campaign is associated with the Kansas Reform Party after a legal challenge had been brought to recognize national Reform Party candidate Ted Weill on the ballot.

George Phillies has filed motions to appear as the Libertarian candidate in New Hampshire with Chris Bennett; it is unclear who will appear on the ballot in that state.

Candidates who have ballot access to enough electoral votes to win the presidency

Other third party candidates

Notes:

• Since Socialist Workers party candidate is Róger Calero is constitutionally disqualified to be President, in some states the Socialist Workers Party has James Harris (JH) listed on the ballot.