The band who were named after the initials of each bandmember, Agnetha Faltskog, her husband at the time Bjorn Ulvaeus, Benny Anderson and his then wife Anni-Frid Lyngstad, went on to sell 385 million records worldwide, with the Beatles being the only act to outsell them.
ABBA's music also went on to inspire the adaptions of Mamma Mia!, watched by over 54 million people around the globe.
With the song contest back in full swing in their native Sweden this year, the band have offered advice to tonight's finalists.
The first one was to take a risk with the song choice, with ABBA having shocked the world back in 1974 by choosing to sing Waterloo in English, instead of their native language.
They also revealed that they almost chose another song as their Eurovision entry, 'Hasta Manana'.
Sharing two tips which he feels could lead to winning the competition, Bjorn Ulvaeus had this to say.
"It might sound ludicrous today, but then it was quite a hard decision to make", he said.
He also added that Waterloo was a solo for Agnetha, as it felt more appropriate for the competition.
"Waterloo was riskier. We took a chance, knowing it was going to be different from all the others. It could have been ‘Hasta Mañana’ and this would never have happened. It would never have won", Ulvaes explained.
Ulvaeus also added that the group made their mark with their choice of outfits on the night. He also spoke about the difficulties of getting into his clothes for the show: "I was overweight and couldn't sit down because my trousers would split".
Elsewhere, the outfits caused more problems, as Bjorn revealed that there was a "mistake" when they were named winners, as the writers had been called up to the stage first.
Bjorn also revealed that he was stopped by a security, who did not believe that he was one of the writers, as "writers don't look like that".
However, Carl Magnus Palm, author of the band's biography Bright Lights, Dark Shadows, stated that ABBA were "intent on making an impression" and "weren't leaving anything to chance".
“You dress up in crazy costumes, you have Napoleon as conductor, everything you could ever think of to make a splash, to make them noticed,” he said.
A few years after winning Eurovision, both couples went their separate ways, with Bjorn and Agnetha divorcing in 1980 following 9 years of marriage. The couple had two children together.
Benny and Anni-Frid also divorced in 1980, having married in 1978 following a 9 year engagement. They did not have children together.
