"LDN" is a single by Lily Allen which was released in the UK on 25 September 2006. It was co-written by Future Cut, and features a sample of "Reggae Merengue", written by Arthur "Duke" Reid and Tommy McCook. The song was originally released on strictly limited edition 7" vinyl (500 copies) in the UK on 24 April 2006, accompanied by album track, "Knock 'Em Out," and was re-released in September following the huge success of Allen's second single "Smile".

There have been two music videos made for "LDN," the first being a low budget affair to promote the original 7" release and the second to promote the re-release.

* The first version of the video, recorded in speed-up camera, follows Allen riding her bike through London. It depicts many positive aspects of London, showing her taking a friendly photograph with a police officer, greeting a passer-by, eating at an ice cream cafe and relaxing in the public park, seeing people playing and having fun.

* The second version of the "LDN" video was produced to be more in line with the song's lyrics, particularly, "When you look with your eyes, everything looks nice, but if you look twice, you can see it's all lies." It opens with Allen in a record store asking the store manager for an eclectic piece of music, satirising keywords that have been used to describe her album - "punky, electronica kindof, grime kinda like new-wave grime, kindof maybe like more broken-beats like kindof dubbie broken beats but a little bit kinda a bit soulful like high drum n bassy but kinda more broken drum and bass".
The video ends with Allen receiving another phone call; her boyfriend has decided not to come. Angry and unhappy, she storms away, and the vivid colour disappears to reveal the duller, more depressing reality of her surroundings..