Lyngstad was born out of wedlock in Ballangen, near Narvik, Norway, as a result of a liaison between Synni - her mother - and a married German sergeant, Alfred Haase, during the German occupation of Norway during the Second World War. Lyngstad believed that her father had died when his ship to Germany was sunk during the war. Only after a German teen magazine Bravo published her bio and a background story in 1977, did Lyngstad discover that her father had not died.

At the end of the war, Lyngstad, her mother, and her grandmother fled to Sweden for fear of reprisals from the Norwegian population, who were angry at those who had had dealings with the Germans. Synni died before Lyngstad was two, so she was brought up by her grandmother in Eskilstuna, Sweden.

Lyngstad got her first job as a jazz singer in 1958, at the age of 13, then formed her own band, the Anni-Frid Four, marrying the bass player Ragnar Fredriksson in 1963, at age 18, with whom she had two children before divorcing.

In 1967 Lyngstad won a TV talent contest, and made an album for EMI. She made a second in 1971, produced by Benny Andersson, laying the foundations for ABBA. She married Andersson on October 6, 1978, divorcing in 1981.

After the break-up of ABBA in 1982, Lyngstad released a moderately successful Phil Collins-produced album, Something's Going On (with the hit single "I Know There's Something Going On"). The follow-up Shine was a total flop and proved her last foray into the international music world. Years later frida recorded a Swedish-language album Djupa Andetag (1996). She finally re-entered the German market in 2004 by recording one song, "The Sun will Shine Again", in conjunction with former Deep Purple member Jon Lord. The song was not released as a single and was only available on an album by Jon Lord released primarily in Germany. Lyngstad appeared with Andersson and Björn Ulvaeus at the London 5th Anniversary performance of the musical based on ABBA songs, Mamma Mia!, in the same year.

In August 26, 1992 Lyngstad married Prince Ruzzo Reuss von Plauen (May 24, 1950-October 29, 1999), of the German Reuss family, who died of cancer at 49 years old. Two years before, her daughter Ann Lise Lotte-Casper (1967-1997) had died at age 30 in a traffic accident in the United States. Her marriage gave her the title of HSH Princess Anni-Frid Reuss von Plauen. Today, Her Serene Highness lives in Switzerland, and sometimes engages in some low profile charity work. Her interest in music is non-existent, a fact she revealed in an interview for her DVD called Frida The DVD which was released in conjunction with her sixtieth birthday in 2005.