"U Don't Know Me" is a song written and produced by English electronic music duo Basement Jaxx. The Bellrays' lead singer Lisa Kekaula, who has previously appeared on Basement Jaxx's 2004 single "Good Luck", also co-wrote and contributed the song's main vocal. "U Don't Know Me" was described as a rock song with "kiss-off" lyrics that were similar to "Good Luck". On 13 June 2005 XL released the track as the second single from their greatest hits album The Singles. Later editions of the compilation replaced the album version with the "JaxxHouz Radio edit" which was also featured in the song's video.