Mamma Mia! Thank You for The Music (released in the USA as Mamma Mia 3!) is a 2028 jukebox musical comedy film written and directed by Ifan Barber, from a story by Barber, Ol Parker, Catherine Johnson and Richard Curtis. It is a follow-up to the 2008 film Mamma Mia! and the 2018 sequel Mamma Mia! Here We Go Again! both of which, like the third instalment, feature music by ABBA. The film features an ensemble cast led by Amanda Seyfried, including Christine Baranski, Julie Walters, Pierce Brosnan, Colin Firth, Stellan Skarsgard and Cher. Both Meryl Streep and Jeremy Irvine return but in different roles to the previous film. The film picks up 15 years after the previous instalment in the franchise, with a now middle-aged Sophie dealing with the challenges of single motherhood after her split from an absent Sky and trying to build a relationship with her teenage daughter while maintaining the Hotel Belladonna.
- Amanda Seyfried as Sophie Sheridan, the owner of The Belladonna Hotel on the Greek Island of Kallikerri, which she inherited from her late mom Donna. She is Bella's mother.
- Christine Baranski as Tanya Chesham-Leigh, one of Sophie's oldest confidants and a dear friend of her mom Donna, she retires to the island with her best friend Rosie at the start of the film.
- Julie Walters as Rosie Mulligan, one of Sophie's oldest confidants and another dear friend of her mom Donna, Rosie also retires to the island with Tanya after leaving her on-and-off boyfriend Bill for good.
- Pierce Brosnan as Sam Carmichael, Sophie's stepfather and one of Sophie's potential biological fathers.