She was confirmed to be appearing in the much-anticipated musical sequel in October.
And Cher gave fans a glimpse of her glamorous grandmother character in Mamma Mia: Here We Go Again on Sunday, as a brand new trailer was aired during the Grammy Awards.
The 71-year-old, clad in a slick white suit and blonde wig, is seen arriving on the Greek island unannounced to 'get the party started', after Sophie and Sky, played by Amanda Seyfried and Dominic Cooper, confirm their pregnancy.
While much of the plot still remains unknown, the trailer revealed the moment Sophie tells husband Sky she is pregnant, causing the pair to share a celebratory and passionate embrace.
The blonde explains she wants to keep the baby a secret, but this soon goes awry when Harry, Sam and Bill admit they have told their friends - before her grandmother, played by Cher, turns up unannounced to celebrate.
Commanding attention as she gets out of her helicopter in a chic white suit, the singer removes her sunglasses and declares upon arrival: 'Let's get the party started!'
Clearly shocked, Sophie then approaches her and says: 'Grandma? You weren't invited...'
To which Cher playfully responds: 'Well, that's the best type of party little girl.'
The new trailer confirmed the sequel will be following the original film and musical in using only the music of ABBA on the soundtrack.
The cast are heard singing and dancing to Eurovision hit Waterloo, while Cher is also heard singing a verse of Fernando against the stunning Greek backdrop.
Sophie is also heard emotionally confessing she 'felt close' to her mother Donna in pregnancy - once again implying she has sadly passed away.
The trailer released last Thursday had caused uproar among fans, who were left disgruntled at the insinuation Meryl Streep's beloved character had been killed off for the sequel.
This article was first published on dailymail.co.uk and is reproduced here with permission.