On a beautiful island in the Greek Aegean Sea, the restaurant run by Donna (Meryl Streep) and her daughter Sophie (Amanda Seyfried) has been particularly lively recently. Sophie is getting married soon, and Donna, who has worked so hard to bring up her daughter alone, is naturally as busy as a bee. In addition to planning her daughter's wedding, she also invited Tonya and Rosie, her best friends who formed a women's rock band together 20 years ago, to prepare for a carnival together. Sophie also secretly sent an invitation to invite three secret guests without telling her mother.
It turned out that Sophie's childhood dream was to hope that her father would appear in person on the wedding day, holding her hand and walking into the church with blessings. Unfortunately, her mother never kept her father's identity a secret. On the eve of the wedding, in desperation, Sophie peeked at her mother's diary, only to find that her mother's three boyfriends were probably her biological father! In order to find out the truth, she had to send invitations to three "friends" her mother hadn't seen for years according to her old address.
To Sophie's surprise, the day before the wedding, three "dads" actually arrived together! Sam (pierce brosnan), Bill (Stellan Skarsgard) and Harry (Colin Firth), all three ex-boyfriends return to this Greek island with different feelings, and each recalls a love affair with Donna. Sophie, who was happy and surprised, intended to leave her three "dads" as a surprise for her mother at the wedding, but unexpectedly found Donna's three old lovers almost fainted with excitement-Mamma Mia, the nightmare is back! On the island before the wedding, unexpected climax followed. Who is Sophie's real father? What kind of sparks will Donna and her three old lovers have? And what kind of joke farce will the sweet wedding event become?