Atomic Kitten are an English girl group formed in Liverpool in 1998, whose current members are Liz McClarnon and Natasha Hamilton. The group was founded by Orchestral Manoeuvres in the Dark (OMD) members Andy McCluskey and Stuart Kershaw, who served as principal songwriters during Atomic Kitten's early years. The group's debut album Right Now was released in October 2000 and charted at number 39 in the United Kingdom. After five top ten singles, original member Kerry Katona quit – four weeks before "Whole Again" reached number one in the UK Singles Chart – and was replaced by former Precious singer Jenny Frost. "Whole Again" became the group's most successful single, staying at number one for four weeks in the UK and six weeks in Germany, and reaching number one in many other territories; in Britain, it was the 13th-best-selling single of the 2000s. The group re-released their debut album, with some tracks re-recorded with Frost's vocals: it peaked at number one in the UK and was certified double platinum after selling over 600,000 copies.

A girl group is a music act featuring several female singers who generally harmonize together. The term "girl group" is also used in a narrower sense in the United States to denote the wave of American female pop music singing groups, many of whom were influenced by doo-wop and which flourished in the late 1950s and early 1960s between the decline of early rock and roll and start of the British Invasion. All-female bands, in which members also play instruments, are usually considered a separate phenomenon. These groups are sometimes called "girl bands" to differentiate, although this terminology is not universally followed.