Best Days of Your Life is a song written and performed by American country artist Kellie Pickler, and co-written by Taylor Swift. It was released on December 1, 2008 as the second single from her self-titled second album. Swift also provides background vocals on the song.
Pickler debuted the song with a performance on November 12, 2008 on the 2008 CMA Awards. She has also performed the song on American Idol, The Ellen DeGeneres Show, and the 2009 CMT Music Awards.
The song debuted at number 56 on the U.S. Billboard Hot Country Songs chart for the week of November 20, 2008. The song has become her biggest hit on the Billboard Hot 100, debuting at number 50 following the song's performance on American Idol. This song has been Pickler's most successful single to date and her first Top Ten hit on the country charts, as well as her first single to surpass 1,000,000 legal downloads, achieving Platinum certification in June 2010. After spending nearly 40 weeks on the country chart, it reached a peak of number nine in August 2009.