Bầu cử tổng thống Hoa Kỳ tại Louisiana năm 2008

The 2008 United States presidential election in Louisiana took place on November 4, 2008, was part of the 2008 United States presidential election. Voters chose nine representatives, or electors to the Electoral College, who voted for president and vice president.

Louisiana was won by Republican nominee John McCain by an 18.6% margin of victory. Prior to the election, all leading news organizations considered this a state McCain would win, or otherwise a "red state". Although Bill Clinton carried the state twice, it has since shifted strongly toward the Republican Party. This is despite having one of the largest percentages of African Americans in the country, one of the Democratic Party's most reliable voting blocs and which gave record-breaking support to Obama, the first African American on a major-party presidential ticket. Its shift to the right has been due almost entirely to its white population, which has become overwhelmingly Republican in the 21st century. It was one of five states to swing Republican from 2004, along with West Virginia, Tennessee, Oklahoma, and Arkansas. This marked the first time that Louisiana failed to back the winning candidate since 1968, when it voted for a third-party candidate George Wallace. In doing so, Obama became the first winning Democratic presidential nominee to lose Louisiana since Lyndon B. Johnson in 1964. He was the first Democrat to ever win without Calcasieu Parish since the parish's founding in 1840.

In this election, Louisiana voted 25.9% to the right of the nation at-large, or a 13.85 percent bigger differential than in 2004. This was the first time since 1988 that either major party won Louisiana in more than two consecutive presidential races.