“You Know I’m No Good” is a song written and performed by English singer Amy Winehouse from her second and final studio album, Back to Black (2006). “You Know I’m No Good” was released as the second single from Back to Black on 5 January 2007. Originally recorded as a solo track, it was remixed with guest vocals from the Wu-Tang Clan member Ghostface Killah. The original appeared on Winehouse’s album, while the version with Ghostface Killah appears on his album More Fish.
In summer 2007, “You Know I’m No Good” was used in advertisements and in the first season opening for AMC’s TV drama Mad Men, although it was replaced with the current theme song for DVD release. It was also used for the opening to ITV’s Secret Diary of a Call Girl. On the recap of The Best Songs of 2007 by Entertainment Weekly magazine, this song ranked at number two.