Björn Ulvaeus: Björn Ulvaeus. Music Department: Mamma Mia!. Björn Ulvaeus was born on 25 April 1945 in Gothenburg, Västra Götalands län, Sweden. He is an actor and composer, known for Mamma Mia! (2008), Mamma Mia! Here We Go Again (2018) and The Martian (2015). He has been married to Lena Källersjö since 5 January 1981. They have two children. He was previously married to Agnetha Fältskog.
Known For: Mamma Mia! (Music Department(guitar, "Waterloo")), Mamma Mia! Here We Go Again (University Professor(uncredited)), The Martian (Soundtrack("Waterloo")), Casanova (Soundtrack("Casanova's Lament"))