Born in Elva, Kerli entered multiple singing competitions before being signed to Island Records in 2006 by LA Reid.

Two songs which were co-written by Kerli for Utopia — "Skyscraper" and "I Feel Immortal" — were later recorded by artists Demi Lovato and Tarja Turunen, respectively.

[11] She was first introduced to music by her kindergarten teacher, who told her mother that Kerli had "nice pitch" and that she was interested in taking her to various singing competitions.

[5][13] She began writing stories, mini books, and poems at the age of 10 to escape from her "abusive" household to an "imaginary world".

[15] In 2002, Kerli competed in the singing competition Laulukarussell in the age group category 13–15 and on 18 May won with the song "Bridge over Troubled Water".

She ended up winning the contest, gaining a singing contract to Universal Republic Records by Rob Stevenson.

While in Stockholm for two years, she worked with numerous producers and due to lack of money as the contracts she had gained previously were unsuccessful, she ate nothing but rice for three months, lived in an abandoned house during winter and slept on a cot.

[20] At the age of 18, she moved to the United States where she continued to perform and write songs, ultimately getting an audition with L.A. Reid, who signed her to The Island Def Jam Music Group in 2006.

[25] On 10 September 2009, Island Def Jam announced Kerli's iPhone application[26] and the first song, "Saima", was released the following month.

[28] Kerli received a European Border Breakers Award for the success of the album Love Is Dead in Estonia.

It contains two songs performed by Kerli, "Tea Party" and "Strange", the latter being a collaboration with Tokio Hotel.

[32] On 19 December 2010, Kerli performed a song in Estonian titled "Sa kuldseks jää" ("Stay Golden") at her grandparents' art show in Estonia.

[39] "Army of Love" peaked at number one on Billboard's Hot Dance Club Songs chart for the week of 7 May 2011.

It was actually first supposed to be a full LP, but as it completely leaked in the middle of December, the label wanted to cut out some songs for March and wanted to release it as an EP; the final official track listing for the EP only includes "Can't Control the Kids", "The Lucky Ones", "Sugar", "Love Me or Leave Me", "Here and Now", "Chemical" and a "The Lucky Ones" remix by one of the Estonian rising DJs Syn Cole, leaving out six songs: "Made For Loving You", "Last Breath", "Supergirl", "Speed Limit", "Kaleidoscope" (which was later released as a Benny Benassi collaboration featuring Kerli), and also "Zero Gravity" was left out, which was first supposed to be on the album too.

[54][55] In October 2012, Kerli participated in ASCAP's week-long songwriting retreat at the Château Marouatte in Dordogne before joining Warner/Chappell Music.

[61] Kerli teamed up with Benny Benassi on 21 July; for a re-edit of "Kaleidoscope", a song originally recorded for her shelved second album Utopia.

[63] In 2014, Kerli co-wrote the song "See Through" by Pentatonix with Joonas Angeria and Thomas Kirjonen for their third extended play, PTX, Vol.

[64] In 2015, Kerli left Los Angeles and returned to Estonia, where she spent nine months with no running water and only her music-making gear to keep her company, where she produced her first independent album.

[70] On 27 July, she released the third single from her upcoming sophomore studio album, "Diamond Hard", along with its music video.

On 22 April 2016, Kerli was featured as a vocalist and co-wrote a song on British artist Katy B's Honey album.

[72] She was later announced to be representing Estonia in the OGAE Second Chance Contest 2017 with "Spirit Animal", held in Warsaw.

[76] On 11 August 2020, Kerli was featured on the album Another Life/Eternally Yours: Motion Picture Collection by the heavy metal band Motionless in White.

[78] Kerli cites Bonnie Tyler and Phil Collins as influences as well as they recorded the only two albums she possessed prior to this.

[13] Among her other influences are Anouk, Joni Mitchell, Janis Joplin,[79] Massive Attack, Kidneythieves, Pendulum, the Cocteau Twins, A Perfect Circle, Deftones, Incubus, Apparat, and Imogen Heap.

Described by Kerli, BubbleGoth is "putting together light and dark, opposites, and things that you don't really necessarily think go together.

"[46] Kerli frequently wears three dots called "moon marks" that represent integrity, love and unity,[89] three things that are also followed by Moon Children: an elaborated fan community/street team established by Kerli in 2006[90] for people who "feel too much and find it hard to exist in this world, so that they wouldn't think they're crazy.

Dubious, her mother told her that if she read "every book in town" on China and wrote a report on it, she would be allowed to get the tattoo.

[83] She has three tattoos on her forearm; one is of a butterfly which symbolises "living every day like it was [her] last" and that she would never "leave a person that [she] loves without them knowing how much [she] loves them", one is the Triple Goddess symbol, and the other states in Latin "Amicus Humani Generis", which Kerli translates "a friend of the human race".

[106] During a live video chat with fans on 7 October 2011, Kerli recalled when she was 17 and would ask her local doctor to sedate her with medication because it "hurt [her] so much to be awake" due to her depression.

She also recalled an instance when she was home alone at age 17, where she covered the windows with dark towels to block out the sunlight and began cutting herself and slitting her arms with rusty scissors, stating that she "wanted to die" and "couldn't feel any physical pain at all because [she] was just hurting so much inside".