Mamma Mia! is a stage musical with a book by British playwright Catherine Johnson, based on the songs of ABBA, composed by Benny Andersson and Björn Ulvaeus. It is an example of a jukebox musical, and is notable for popularising the genre. The plot is adapted from the 1968 film Buona Sera, Mrs. Campbell starring Gina Lollobrigida.

Although the title of the musical is taken from the group's 1975 chart-topper "Mamma Mia", the musical's plot has nothing to do with the story of the group itself.

Björn Ulvaeus and Benny Andersson, who composed the original music for ABBA, have been involved in the development of the show from the beginning. Anni-Frid Lyngstad has been involved financially in the production, while Agnetha Fältskog has not, though she was present at the Swedish premiere and final show.

The musical includes such hits as "Super Trouper", "Dancing Queen", "Knowing Me, Knowing You", "Thank You for the Music", "Money, Money, Money", "The Winner Takes It All", "Voulez Vous", "I Have a Dream" and "SOS". It had been seen by over ten million people worldwide as of July 2003. Estimates of 2007, is that 30 million have now seen Mamma Mia!. Since its opening in 1999, the production has grossed US$2.0 billion in earnings.

A film version of Mamma Mia!, starring Meryl Streep, Colin Firth, Pierce Brosnan, Amanda Seyfried, Christine Baranski and Julie Walters began shooting in June 2007 and premiered in July 2008.