Anni-Frid Synni Lyngstad was born in Bjørkåsen, a small village in Ballangen near Narvik, in northern Norway, to a Norwegian mother, Synni Lyngstad (19 June 1926 – 28 September 1947), and a German father, Alfred Haase (29 June 1919 – 23 February 2009), who was a sergeant in the Wehrmacht, not long after the end of the Second World War and the German occupation of Norway. Haase returned to Germany when his unit was evacuated.

In early 1947, Anni-Frid, her mother Synni, and her maternal grandmother, Arntine "Agny" Lyngstad, left their birthplace, fearing reprisals against those who had dealings with the Germans during the occupation. Anni-Frid was taken by Agny to Sweden, where they settled in the region of Härjedalen. Her grandmother took any available job while living there, whereas Synni remained in Norway and worked for a period in the south of the country. Synni joined her mother and daughter in Sweden, and the three moved to Malmköping (72 km from Stockholm). Synni died of kidney failure soon afterwards, aged 21 years, leaving Anni-Frid to be raised solely by her grandmother.

In June 1949, they both relocated to Torshälla, outside Eskilstuna, where Agny worked as a seamstress. Anni-Frid grew up in Torshälla and began to attend school on August 1952. During her childhood, Anni-Frid had close contact with her family, notably her uncle and four aunts, at her birthplace during summer holidays. She was close to her aunt, Olive, who once stated that she saw how lonely and subdued Anni-Frid was, and, consequently, always did her best to make Anni-Frid feel loved and welcomed, during her visits.

At the age of 13, Lyngstad got her first job as a dance band and schlager singer in 1958, with the Evald Ek's Orchestra. Evald Ek himself remembers: "It was hard to believe, such a young person could sing that well. She was so easy to rehearse with and she was never shy onstage. The only thing I taught her was to sing out. In those days, she had a tendency of holding back her voice a little." With the Evald Eks Orchestra, the 13-year-old Lyngstad, performed every weekend in front of a dancing audience. The sets often lasted up to five hours. The songs she liked most to sing were the evergreens; "All of Me", "Night and Day" and "Begin the Beguine". To advance and develop, she also started to take singing lessons. Later, she teamed up with a 15-piece 'big band', who performed a jazz repertoire covering Glenn Miller, Duke Ellington and Count Basie; her vocal idols being Ella Fitzgerald and Peggy Lee. In 1963, she formed her own band, the Anni-Frid Four.

On 3 April 1964, at age 18, Frida married salesperson and fellow musician Ragnar Fredriksson. They had two children: Hans Ragnar (born 26 January 1963) and Ann Lise-Lotte (25 February 1967 – 13 January 1998). They separated in 1968 and were officially divorced on 19 May 1970. On the very same day, Lyngstad's grandmother, Arntine, died, aged 71.

On 11 September 1967, Frida recorded the vocals for "En ledig dag", which was to become her first single for EMI Sweden, under the sub-label, His Master's Voice. Professional and self-assured on this first day in the studio, she recorded the vocals in just one take. The early songs she recorded for EMI are included in the compilation album, Frida 1967-1972, digitally remastered and released by EMI Sweden in 1997.

On 29 January 1968, she performed this song on 'Studio 8' on national television and on this occasion briefly met Future ABBA member Agnetha Fältskog, who also performed her first single on the same SVT1 programme. Lyngstad toured Sweden in 1968, and recorded several singles for EMI. At the same time, she decided to move to Stockholm to start working full-time as a singer.

In 1969, she participated in Melodifestivalen, the Swedish heats for the Eurovision Song Contest, with the song "Härlig är vår jord" ("Our Earth Is Wonderful"), and finished in fourth place. In the backstage she met her Future husband and ABBA band mate Benny Andersson.

At first, Lyngstad was hesitant to perform with her boyfriend Benny Andersson, his best friend Björn Ulvaeus and his wife, Agnetha Fältskog. Their first project together was the cabaret act Festfolket, which was not a success, in the winter of 1970–1971. The following year, Lyngstad toured on her own, while the other three Future ABBA members started performing together on a regular basis. Eventually, she rejoined the ensemble. Andersson and Ulvaeus were busy producing other artists, but soon discovered the qualities of Lyngstad's and Fältskog's voices combined; thus, the band was formed initially as Björn & Benny, Agnetha & Anni-Frid, later renamed ABBA.

Her first album, Frida, produced by her then-fiancé Benny Andersson, was released in 1971. The album received unanimously generous praise from critics and the press, who especially noted the precision and versatility of Lyngstad's voice. For Example, Sweden's biggest morning paper Dagens Nyheter (Daily News) wrote: "Professional, sure and certain LP-debut ... low-key but self-assured personality with sprinkles of temperament, humor and tenderness. And she sings in such a way that you understand that she's got something between her ears – she sings, in other words, in a very intelligent way". She now scored her first Swedish No.1 hit with "Min Egen Stad" ("My Own Town"). All four Future members of ABBA sang back-up vocals on this song. The album is now included in the EMI compilation Frida 1967-1972.

Frida continued to play in cabarets, and tour and regularly perform on TV and radio. Subsequently, her relationship with Andersson, and friendship with Björn Ulvaeus and Agnetha Fältskog led to the formation of ABBA. In 1972, after five years at EMI Sweden, Lyngstad changed record companies and moved to the Polar Music label. She recorded the single "Man vill ju leva lite dessemellan" ("One wants to live a little from time to time"), which became her second No. 1 hit on the Swedish charts.

Her next solo album, in Swedish, was Frida ensam (Frida Alone), released in 1975 during the ABBA years, and produced by Benny Andersson. This album includes her successful Swedish version of "Fernando", which stayed at the No. 1 spot in the Svensktoppen radio charts for 9 weeks, but was never released as a single. The album was recorded between sessions of the ABBA albums "Waterloo" and "ABBA". Due to the rising popularity of the group, the album took 18 months to record. Frida ensam became an enormous commercial and critical success in Sweden, topping the Swedish album charts for six weeks and remaining in the charts for 38. The album was mostly a collection of covers of songs by artists like the Beach Boys ("Skulle de' va' skönt"), 10cc ("Guld och gröna ängar") and David Bowie ("Liv på Mars?"), receiving positive reviews from Melody Maker: "The album portrays Frida as a very strong and emotive singer and shows the true value of the music, that if sung properly and with enough feeling it transcends all language barriers". This album was such a big success, it eventually went platinum.

Lyngstad believed that her father, Alfred Haase, had died during the war on his way back to Germany as his ship was reported to have sunk. However, in 1977, the German teen magazine Bravo published a poster and a complete biography with details of Lyngstad's background, including the names of her mother and father. It was seen by Lyngstad's half-brother, Peter Haase, who went to his father and asked him if he had been in Ballangen during the war. A few months later, Lyngstad met Haase in Stockholm for the first time.

In 1969, Lyngstad met Benny Andersson. By 1971, they were living together, but did not marry until 6 October 1978, during the height of ABBA's success. However, after only two years of marriage, they separated on 26 November 1980, and were divorced in 1981.

According to Dagens Nyheter and Sveriges Radio, Lyngstad is a former supporter of the Swedish Moderate Party. She appeared in a Swedish Employers Association advertisement "Satsa på dig själv" (English: Set on yourself) in 1979, which caused controversy and objections, especially from Mikael Wiehe, who rejected her offer to record her cover version of his song, Flickan och kråkan due to political differences, in the 1980s.

In 1982, Lyngstad won the Swedish music prize Rockbjörnen for the Best Female Artist. She was inducted in the Rock and Roll Hall of Fame as a member of ABBA on 2010, and represented the group in their acceptance speech, along with Benny Andersson. In 2014, she was awarded with the Eskilstuna Music Prize for her "pioneering career" and significant contribution to popular music as an "icon" who "left an indelible imprint in musical history."

In 1983, Lyngstad assisted with Abbacadabra, and recorded one of the tracks with two different male vocalists in different languages, including Frenchman Daniel Balavoine on the track "Belle" and on the English version "Time" with B. A. Robertson. This track was a cover of "Arrival", an instrumental track from the ABBA album of the same name.

Lyngstad's next album was the ambient Shine (1984). This album was recorded at Studios De La Grande Armée in Paris, France and produced by Steve Lillywhite, known for his work with artists like Peter Gabriel, U2, the Rolling Stones, Morrissey and Kirsty MacColl amongst others. Lillywhite was only 29 when this album was recorded and he gave Frida a very experimental sound and managed to create a relaxed atmosphere in the studio. The album had much less success than hoped, though it reached the Top 20 in many European countries, No. 6 in Sweden being its highest position.

In 1987, Frida was in the choir for the recording of her former husband Benny Andersson's song "Klinga Mina Klockor". Also in 1987, Lyngstad recorded the single "Så Länge Vi Har Varann" ("As Long As We Have Each Other") with the Swedish pop group Ratata, one of Lyngstad's favourites. She was contacted by singer Mauro Scocco, who mentioned that he had a song suitable for a duet. After hearing it, Lyngstad accepted immediately. The song achieved great success in Sweden, and was also recorded in English under the title of "As long as I have you". An English-language video of the song was produced, although an Australian release of this song on Festival Records in January 1998 was eventually shelved.

In 1988, Lyngstad became a grandmother when her daughter, Ann Lise-Lotte married to an American, Charles Geritt Casper, and gave birth to a son named Jonathan Casper.

In 1990, Lyngstad became a member of the committee of the Swedish environmental organization Det Naturliga Steget (The Natural Step). The organization wanted a "famous face" to help them reach the public, and in 1991 she became chairwoman for the organization Artister För Miljö (Artists For The Environment). In 1992, Lyngstad performed live at the Stockholm Water Festival at the Kings Castle and released the environmental charity single with her cover of Julian Lennon's song "Saltwater". All the royalties from this single went to charity. In 1993, on Queen Silvia's 50th birthday, Frida was asked to perform "Dancing Queen" on stage, as performed by ABBA when the king and queen married in 1976. Frida contacted The Real Group and together they performed the song at the Stockholm Opera House in front of the king and queen. The Swedish prime minister at the time, Ingvar Carlsson, also present that night, said it was an ingenious step to do "Dancing Queen" a cappella. This performance was filmed by Swedish TV and can be seen in Frida - The DVD.

On 26 August 1992, Lyngstad married the Prince of House of Reuss, Heinrich Ruzzo. She became the stepmother of the Prince of Reuss of Plauen's two daughters, Princess Henriette Anna-Bess Helle Mette Reuss, Countess of Plauen, and Princess Pauline Margaretha Emma-Louise Mette Reuss, Countess of Plauen (both born 2 June 1977, Oslo, Norway), who are twins.

In 1996, Lyngstad recorded her Swedish language album Djupa andetag (Deep Breaths). It was a long-awaited album as 12 years had passed since Shine was released. The album attracted overall relatively positive reviews and was a success in Sweden where it reached No. 1 on the album chart. Frida did many TV appearances in Sweden, Norway, Denmark and Finland to promote the album. Djupa andetag was one of the first Swedish albums to be released as a combined audio-video CD-ROM, including interviews with Lyngstad, footage from the making of the album, as well as promotional videos. Despite the fact that Djupa andetag was officially only released in Scandinavia and the songs were entirely sung in Swedish, a remix album of the single tracks "Även en blomma", "Alla Mina Bästa År" (a duet with Roxette's Marie Fredriksson) and "Ögonen" was released in Germany in 1998, entitled Frida - The Mixes. Despite the success of the album, none of these singles made a big impression on the Swedish charts. A one-hour documentary about the making of this album, both in the studio and from Frida's home in Mallorca, Spain, can be seen in Frida - The DVD. A follow-up album with Producer Anders Glenmark was reportedly in the works, but was shelved due to the death of Frida's daughter in 1998. Lyngstad dedicated the song "Chemistry Tonight" (co-written by Kirsty MacColl) to the Songwriter after MacColl's death in 2000.

On 13 January 1998, Lyngstad's daughter from her first marriage, Ann Lise-Lotte Casper (née Fredriksson), died of injuries sustained in a car accident in Livonia, New York, a town 20 miles south of Rochester, New York, aged 30 years. Heinrich Ruzzo died of lymphoma in October 1999, leaving Lyngstad the Dowager Princess of Reuss.

A few low key and one-off recordings followed, including a 2002 duet with opera singer Filippa Giordano of the "Barcarolle" from Jacques Offenbach's Les contes d'Hoffman as well as the song "The Sun Will Shine Again", written by former Deep Purple member Jon Lord, and recorded in 2004. "Barcarolle" is only available on the Japanese edition of Giordano's album Rosso Amore and "The Sun Will Shine Again" can be found on Jon Lord's album Beyond The Notes (although a limited-promotional single had been made available). Lord and Lyngstad made several TV appearances in Germany performing the song, on shows like The Sunday Night Classics and The Golden Henne Gala. Lyngstad also joined Lord on stage singing the song during his European autumn tour in 2004. During this tour, she also performed "In the Bleak Midwinter", a performance of which can be found on social media.

For the 2004 semi-final of the Eurovision Song Contest, staged in Istanbul thirty years after ABBA had won the contest in Brighton, Lyngstad appeared in a special comedy video made for the interval act, entitled Our Last Video. All four members of the group appeared briefly in cameo roles, as did the singer Cher and British Comedian Rik Mayall amongst others. The video was not included in the official DVD release of the Eurovision Contest, but was issued as a separate DVD release on the Universal Music label. It was billed as the first time the four had worked together since the group split in 1982 although they each filmed their appearances separately. Also in 2004, Lyngstad appeared with former bandmates Benny Andersson and Björn Ulvaeus in London at the fifth anniversary performance of Mamma Mia!, the musical based on ABBA songs. In 2005, she joined all three of her former ABBA colleagues at the Swedish premiere of Mamma Mia! at the arena Cirkus in Stockholm.

On 15 November 2005, to celebrate Lyngstad's 60th birthday, Universal Records released the box set Frida – 4xCD 1xDVD, consisting of all the solo albums she recorded for Polar Music and Anderson Records, all digitally remastered and including a set of bonus tracks. Also included was Frida - The DVD, a 3½ hour documentary where Lyngstad talks about her entire career in the music Business. Filmed in the Swiss Alps, she talks about her singing technique and about her career both before and after ABBA, and explains how songs were performed and recorded. In collaboration with Swedish TV, SVT, the film included many rare TV clips from her early performances, such as her first TV performance with "En Ledig Dag", ("A Day Off"). Also included are TV documentaries about the making and recordings of Something's Going On and Djupa andetag (Deep Breaths).

Lyngstad is a vegetarian and a self-proclaimed feminist. Currently sharing a home with her British boyfriend Henry Smith, 5th Viscount Hambleden at Zermatt, Switzerland since 2008, she remains involved in charity work.

On 16 February 2011, BBC Radio 4 broadcast a 45-minute play featuring Frida and the play's Writer, long term fan and performer Christopher Green. The play, Like an Angel Passing Through My Room, was billed as "a story about love. The unconditional love of a devoted fan ... about a real and an imagined intimacy." It was a project several years in the making; what started as an upbeat reflection on fame and the notion of being a fan, developed into a meditation on the communication between two people and coping with the blows life deals. In an interview with Frida she and Green talked about her long recovery following the death of her husband in 1999. The play is reflective but with a comic sensibility. Frida stated in 2004 that she never intended to return to the music industry although this was short lived and Future studio albums were discussed in 2010. Nothing ever came of them and Frida has not returned to recording music since.

In 2013, Frida helped organise the opening of ABBA: The Museum in Stockholm stated she wanted to "let ABBA rest". The long-awaited ABBA reunion was expected to happen in 2014 to celebrate the 40th anniversary of the group's win at the Eurovision Song Contest. However, this did not happen.

In 2015, Frida, along with Dan Daniell, released the single "1865" about the Matterhorn in Switzerland.

On 19 August 2017, Lyngstad travelled to Torshälla to claim her award from the Eskilstuna Music Prize 2014.