The 2008 United States Senate election in Kentucky was held on November 4, 2008. Minority Leader and incumbent Republican U.S. Senator Mitch McConnell won re-election to a fifth term. Although Barack Obama lost Kentucky by a 16.22% margin to John McCain in the concurrent presidential election, McConnell more narrowly kept his seat with a 5.94% margin against businessman Bruce Lunsford. This was a greatly reduced margin from when he won re-election in 2002 with a 29.4% margin.

Addison Mitchell McConnell III is an American politician and retired attorney who has served as Senate Minority Leader since 2021 and the senior United States senator from Kentucky since 1985, the longest serving senator in his state's history. He previously served as minority leader from 2007 to 2015, majority leader from 2015 to 2021 and was majority whip from 2003 to 2007. McConnell has been the leader of the Senate Republican Conference since 2007, making him the longest serving Senate party leader in U.S. history.