Young Donna, Sam and Harry forge relationships that resonate in the present. Mamma Mia! Here We Go Again is an upcoming American-British-Swedish romantic comedy musical film directed and written by Ol Parker. It is a sequel to the 2008 film Mamma Mia!, which is based on the musical of the same name. The film stars Amanda Seyfried, Lily James, Christine Baranski, Julie Walters, Pierce Brosnan, Colin Firth, Stellan Skarsgård, Dominic Cooper, Andy Garcia, Cher, and Meryl Streep.