As of September 2021, what is the pop group ABBA's only million-selling single in the UK?

As of September 2021, "Dancing Queen" is ABBA's biggest song in the UK, being their only million-seller with 1.65 million chart sales, including 93 million streams since 2014.

ABBA are a Swedish pop group formed in Stockholm in 1972 by Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad. The group's name is an acronym of the first letters of their first names arranged as a palindrome. One of the most popular and successful musical groups of all time, they became one of the best-selling music acts in the history of popular music, topping the charts worldwide from 1974 to 1983, and in 2021. ABBA have achieved 48 hit singles.

"Dancing Queen" is a Europop song by the Swedish group ABBA, released as the lead single from their fourth studio album, Arrival. It was written by Benny Andersson, Björn Ulvaeus and Stig Anderson. Andersson and Ulvaeus also produced the song. "Dancing Queen" was released as a single in Sweden on 15 August 1976, followed by a UK release and the rest of Europe a few days later. It was a worldwide hit.