Mamma Mia! is a musical movie based on the songs of ABBA, following a young bride-to-be's quest to discover the identity of her father before her wedding, resulting in the arrival of three men from her mother's past.
The Mamma Mia! poster's title font resembles Bodoni Poster Compressed, with a slightly altered exclamation mark. Bodoni Poster Compressed is a commercial font, and additional information about it can be found here.