"Karma Chameleon" is a song by British New Wave band Culture Club, featured on the group's 1983 album Colour by Numbers. The song spent three weeks at number one on the US Hot 100 in 1984, becoming the group's biggest hit and only US number one. "Karma Chameleon" hit number one in sixteen countries worldwide. In the group's home country, it became the second Culture Club single to reach the top of the UK singles chart, where it stayed for six weeks in September and October 1983, and became the biggest-selling single of 1983.

In an interview, Culture Club frontman Boy George explained: "The song is about the terrible fear of alienation that people have, the fear of standing up for one thing. It's about trying to suck up to everybody. Basically, if you aren't true, if you don't act like you feel, then you get Karma-justice, that's nature's way of paying you back."

The prominent harmonica part was played by Judd Lander, who had been a member of Merseybeat group The Hideaways in the 1960s. The song was originally to be called "Cameo Chameleon". The band were recorded in interviews in late 1983 stating this was to be the title of their next single.

Likely because of the lyric "I'm a man without conviction," and the chorus, which repeats the word "chameleon," "Karma Chameleon" has been used by several politicians in political ads. In 2006, Britain's Labour Party used "Karma Chameleon" as the theme song for a series of political advertisements against Conservative party leader David Cameron in the 2006 UK Elections. Also, during the 2010 U.S. senate race in Pennsylvania, Republican Pat Toomey used the song as backing music for his video "Happy Anniversary Arlen Specter!" as a way to criticize a sitting Senator from Pennsylvania and recently-turned Democrat Arlen Specter.

The song won Best British Single at the 1984 Brit Awards.

The "Karma Chameleon" music video was filmed at Desborough Island in Weybridge during the summer of 1983. According to caption, the video is set in Mississippi in 1870, and depicts people in colourful costumes, including dancers in "red, gold and green", waiting on a riverbank. Boy George is dressed in a colourful costume and is depicted singing the title song. A pickpocket is seen wandering through the crowd.

A riverboat, "The Chameleon", arrives and people board. A game of cards takes place, as Boy George continues to sing in the background. The pickpocket is discovered cheating and is forced to walk the plank. Throughout the video, Blacks and Caucasians are depicted singing and dancing together.

The boat used in the video belongs to Turk Launches of Kingston-upon-Thames, and it is still in use, mainly on the Kingston to Hampton Court route during the summer months.