Björn Ulvaeus was born in Gothenburg, when he was a young child his family moved to Västervik.  Björn studied business and law at Lund University after doing his military service with stand-up comedian Magnus Holmström. Björn was a member of the Swedish folk/schlager band Hootenanny Singers who had an enormous following in Scandinavia. While on the road in southern Sweden in 1966, they encountered the Hep Stars, and Björn quickly became friends with the group’s keyboard player, Benny Andersson. The two musicians shared a passion for song writing, and each found a composing partner in the other. On meeting again that summer, they composed their first song together: "Isn't It Easy To Say"; a song soon to be recorded by Benny’s group. The two continued teaming up for music, helping out each other's bands in the recording studio, and adding guitar or keyboards respectively to the recordings. In 1968, they composed two songs together: "A Flower In My Garden", recorded by Hep Stars, and their first 'real' hit "Ljuva Sextiotal", for which Stig Anderson wrote lyrics. The latter - a cabaret-style ironic song about the 1960s - was submitted for the 1969 Swedish heats for Eurovision Song Contest, but was rejected; it was later recorded by diva Brita Borg. Another hit came in 1969 with "Speleman", also recorded by Hep Stars. While filming a TV special in March 1969, Björn met eighteen-year-old singer/songwriter Agnetha Fältskog. Benny had himself met his future spouse, 24-year old jazz vocalist Anni-Frid Lyngstad, only weeks before. Björn continued recording and touring with Hootenanny Singers to great acclaim while working as in-house producer at Polar Record Company (headed by future manager Stig Andersson), with Benny as his new partner. The twosome produced records by other artists and continued writing songs together. Polar artist Arne Lamberts Swedish version of "A Flower In My Garden" - "Fröken Blåklint" - was one of Björn & Benny’s first in-house productions. In December 1969, they recorded the new song "She's My Kind Of Girl", which became their first single as a duo. It was released in March 1970, giving them a minor hit in Sweden (and by chance a top-ten hit in Japan two years later). The Hootenanny Singers entered Svensktoppen, the Swedish radio charts, in 1970 with "Omkring Tiggarn Från Luossa", a cover of an old folk/schlager song. It remained on the charts for 52 consecutive weeks, a record which endured until 1990; the song was produced by Björn and Benny, and had Bjorn’s solo vocal and Benny's piano. On 6 July 1971, Björn married Agnetha Fältskog. Their first child, Linda Elin Ulvaeus was born  February 23 1973.  Their second child, Peter Christian Ulvaeus was born December 4, 1977 at the height of ABBA’s world success. In 1979 Björn and Agnetha separated and were officially divorced in July 1980. They both agreed to remain in ABBA as it showed it was not the group that caused their split. Björn then married music journalist Lena Kallersjö on 6 January 1981. This marriage produced another two daughters: Emma (born in 1982) and Anna (born in 1986). From 1984 to 1990 they moved to the UK. They currently live back in Stockholm. After ABBA, Björn and Benny, created the musicals Chess, Kristina från Duvemåla (based on The Emigrants novels by Swedish writer Vilhelm Moberg), and Mamma Mia! (Based on ABBA songs). In 1985, Bjorn and Benny wrote, produced and released an album with brother and sister Anders and Karin Glenmark, featuring new songs by Andersson/Ulvaeus. The duo named themselves Gemini, and a second album with more music by Björn and Benny was released in April 1987, containing the big hit "Mio My Mio From the late 1980s, he together with Benny worked on an idea for an epic Swedish language musical based The Emigrants novels by Swedish writer Vilhelm Moberg. Benny wrote all the music and Bjorn wrote the text using the original Swedish books as a guide. "Kristina från Duvemåla" was first released as a 3 CD set and scored # 1 singles “Du Musta finnas” and Guldet blev till sand”. In October 1995, the stage production premiered in Sweden. The musical ran successfully for almost five years, before closing in June 1999. Although he didn’t know it to start with his next project for the next 10 years or so was the musical Mamma Mia!,. The musical has become a worldwide box-office blockbuster. Next was Mamma Mia the movie which premiered on 18 July 2008 and has now become the most successful movie musical of all time and has been named the number one box office smash of 2008, and the biggest-selling DVD ever in the UK.

Together with Benny, Björn was nominated for the Drama Desk Award in the category "Outstanding Music" (for the musical Chess), and for a Tony Award in a category "Best Orchestrations" (for musical Mamma Mia!). Original cast recordings of both musicals were nominated for a Grammy Award. Björn is a member of the International Humanist and Ethical Union's Swedish member organisation Humanisterna, and was awarded their annual prize, Hedenius-priset, in 2006. Björn also shared with Benny "The Special International Ivor Novello Award" from 'The British Academy of Composers and Songwriters', "The Music Export Prize" from the Swedish Ministry of Industry and Trade (2008), and "Lifetime Achievement Award" from the Swedish Music Publishers Association (SMFF). The boys often write for "Benny Andersson's orchestra", with Bjorn providing lyrics to new material written by Benny. Björn wrote new Swedish lyrics for the re-recording of two old songs of the Glenmark duo Gemini. Björn also wrote new English lyrics to older Swedish language songs for opera singer Anne Sofie Von Otter’s tribute album "I Let The Music Speak". Benny has written the music to songs recorded by Anders Ekborg ("Han Som Har Vunnit Allt"] and Barbara Dickson ("The Day The Wall Came Tumbling Down") with lyrics by Bjorn. Björn has revealed that he suffers from severe memory loss and now no longer remembers many important events in his life. He now has little memory of some of the critical events in his professional history and has resorted to images of his past and even hypnotism to try and bring back his memory. In 2009 he worked with Benny on the first English album for Benny’s band “The Benny Andersson Band” The album included a new Benny and Bjorn song, STORY OF A HEART. The English language versions of Kristina från Duvemåla , now simply called Kristina premiered in New York in 2009.

Björn is currently working on the latest staging of Kristina in Finland .

Björn is now involved in the running of ABBA THE MUSEUM in Stockholm Plus POP House hotel at the Museum and Mamma Mia The Party which opened in Sweden in 2016

Excerpts taken from Wikipedia,/Carl Magnes Palm /Polar Music. Compliled and written by ABBA-official 2009