Aqua is a Danish dance-pop group, perhaps best known for their 1997 breakthrough single "Barbie Girl". The group formed in 1989, and achieved huge success across the globe in the late 1990s and early 2000s. The group managed to top the UK Singles Chart with their first three singles, a feat few artists have achieved. The group released two albums: Aquarium in 1997 and Aquarius in 2000, before splitting up in July 2001. The group sold an estimated 30 million albums and singles, making them the most successful Danish band ever. The band was formed by Lene Nystrøm Rasted (vocals), Rene Dif (vocals), Søren Rasted (keyboard) and Claus Norreen (guitar).

In their prime, Aqua's singles managed to chart top ten in a number of countries where European pop acts would not normally succeed, including the United States, Australia, and Japan. The group also caused controversy with the double entendres in their "Barbie Girl" single, with the Barbie doll makers Mattel filing a lawsuit against the group. The lawsuit was finally rejected in 2002.

Since their 2001 split, Nystrøm, Dif and Rasted have all achieved solo chart success, and Norreen has continued in the music industry remixing other artists' material.

The group has announced the upcoming release of a compilation album featuring new material, and the four original members have confirmed Aqua will reunite for a tour in 2008. This was confirmed at a press event Friday on October 26, 2007.