"Under My Skin" is a song by German recording artist Sarah Connor from her sixth studio album, Sexy as Hell (2008). Written by Remee, Thomas Troelsen, Lucas Secon, and produced by Remee and Troelsen, the song was released as the album's lead single on 1 August 2008 in German-speaking Europe. Connor's first uptempo single release since 2005's "From Zero to Hero", the track managed to reach the top twenty in Austria and on a composite European Hot 100 Singles chart, as well as number four in Germany, where it became her highest-peaking single since her 2006 Christmas song "The Best Side of Life".

The writers of the song had sold the single to two separate companies. One being Connor's and the other being SM Entertainment, a South Korean music company. The song was sold with the understanding that Connor's version could only be released within North America and European regions and Australia and SM Entertainment could only release the song in Asian regions of the world. SM artist TVXQ used the song as the lead single in their 4th studio album Mirotic and it went to number one in Japan.

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