Mamma Mia! Here We Go Again is a 2018 jukebox musical romantic comedy film written and directed by Ol Parker, from a story by Parker, Catherine Johnson, and Richard Curtis. It is the sequel and prequel to the 2008 film Mamma Mia!, which in turn is based on the 1999 eponymous musical using the music of ABBA. The film features an ensemble cast, including Christine Baranski, Pierce Brosnan, Dominic Cooper, Colin Firth, Andy García, Lily James, Amanda Seyfried, Stellan Skarsgård, Julie Walters, Cher, Meryl Streep, Alexa Davies, Jessica Keenan Wynn, Josh Dylan, Jeremy Irvine, and Hugh Skinner. Both a prequel and a sequel, the plot is set after the events of the previous film, and is intersected with flashbacks to Donna's youth in 1979, with some scenes from the two time periods mirroring each other.

Due to the financial success of the first film, Universal Pictures had long been interested in a sequel. The film was officially announced in May 2017, with Parker hired to write and direct. In June 2017, many of the original cast confirmed their involvement, with James being cast in the role of Young Donna that July. Filming took place from August to December 2017 in Croatia (most prominently Vis), Bordeaux, Stockholm, Oxford, Hampton and at Shepperton Studios. A British and American joint venture, the film was co-produced by Playtone, Littlestar Productions, Perfect World Pictures, and Legendary Entertainment.

Mamma Mia! Here We Go Again was premiered at the Hammersmith Apollo in London on 16 July 2018, and was released in the United Kingdom and the United States on 20 July 2018, ten years to the week after its predecessor's release, in both standard and IMAX formats. The film was a box office success, grossing $402 million worldwide and received generally positive reviews, as an improvement over its predecessor with critics praising the performances and musical numbers. The film is dedicated to the memory of production designer Alan MacDonald.