Since its release in 2014, her collection Milk and Honey has sold over 11 million copies and was translated into 43 languages,[2] spending 77 weeks on the New York Times Best-Seller List.

[6] Her family eventually settled in Brampton, Ontario, alongside a large South Asian diaspora community, while Kaur's father worked as a truck driver.

[14] Her relationship with her parents, in particular her mother, became turbulent in her adolescence; there were extensive arguments over mundane activities that Kaur later interpreted as a result of wishing to preserve their original culture.

[15][16] As a young child she witnessed relatives and friends experience domestic violence or sexual abuse; watching her parents be subject to racism, she inferred, resulted in her coy disposition.

[10][20] Kaur aspired to be an astronaut or a social worker or a fashion designer; her ambitions changed frequently and her father prohibited her from studying the latter subject in university.

[23] Throughout middle school she partook in "speech competitions", winning one in seventh grade, thus helping her find progress and hope in spite of isolation and bullying.

[29] Although she found spoken-word poetry "really natural", describing her first show as "Like a damn hug", she'd fidget with the paper above her face, leaving before audiences clapped due to her anxiety.

[32] Kaur started writing in an attempt to articulate her personal trauma, having just left an abusive relationship – which influenced her decision to perform poetry: "I wanted to find a voice, because I had been voiceless for so long".

[33][34][16] At university, her writing became more reflective than before, having previously written about boys she liked and the political changes she wanted to see in the world – although she was, by her own admission, ignorant on the matter, her poems at first lambasted the Canadian government.

[43][44] Kaur recalled that she was hesitant to submit to magazines or journals because it "felt like I was taking apart [Milk and Honey] and throwing things at different walls, hoping they would stick.

[13] She later regretted writing her response, finding widespread disdain affected her mental health, experiencing anxiety that "sort of set in and never really left" and suicidal thoughts for a period of time.

[13] As Kaur rose to prominence on social media, Milk and Honey was re-released by Andrews McMeel Publishing, which saw her work alongside an editor for the first time.

"[56][57] they convinced me i only had a few good years left before i was replaced by a girl younger than me as though men yield power with age but women grow into irrelevance they can keep their lies for i have just gotten started i feel as though i just left the womb my twenties are the warm-up for what i'm really about to do wait till you see me in my thirties now that will be a proper introduction to the nasty, wild, woman in me, how can i leave before the party's started rehearsals begin at forty i ripen with age i do not come with an expiration date and now for the main event curtains up at fifty let's begin the show Following a three-month writing trip in California, and in the same year as her induction into the Brampton Arts Walk of Fame, Kaur's second book, The Sun and Her Flowers, was published, on 3 October 2017.

[22][49] During the COVID-19 pandemic, Kaur moved back in to her parents' house in Brampton and began teaching workshops on Instagram Live, due to feelings of loneliness and fear and a desire to connect with her audience.

[77] Since Gurmukhi script has no concept of separate lower and upper case, her work is written exclusively in lowercase,[78] using only the period as a form of punctuation; Kaur writes this way to honour the Punjabi language.

[59] Kaur's style ranges from aphoristic, inspirational and confessional, although her poems aren't "100 percent autobiographical" – the fictional elements being often opaque in regards to their authenticity.

[92] Alongside her peers – Nayyirah Waheed, Lang Leav, Warsan Shire – and other "Instapoets", Kaur's plainspoken and free verse poetry is delivered in a "bite-size" manner – some poems only composed of one line.

[97][98] Due to her usage of dry, open-ended, and colloquial language, Kaur has been said to break from and reject traditional standards and features of poetry which are held in importance.

[43][101][102] Literature scholar Alyson Miller wrote that Kaur makes use of "gendered yet ostensibly universal themes relating to sexism, trauma, friendship, and violence".

[107] Kaur has described Beyoncé as an influence, as well as Sharon Olds, Marina Abramović, Adele, Kahlil Gibran, Nizzar Qabbani, Amrita Sher-Gil and Frida Kahlo.

Kaur' poetry explores a small selection of themes alongside issues faced by Indian women and immigrants, female trauma and the "South Asian experience".

[5] Feminism, refugees, immigration and her South Asian identity became more prominent in The Sun and Her Flowers, alongside musings on body dysmorphia, abuse, rape and self-love.

[62][117] Regarded as a "pioneer" of the "Instapoet" style, Erica Wagner noted Kaur's influence in what she called the "biggest overall shift [in reading habits] we've seen in the past decade".

[13][93] Her poetry has been credited with "inspir[ing] [a] hub of creativity for young black girls"; author Tanya Byrne argued that fellow BAME writers should replicate Kaur's self-publishing.

[119] "Kaur has become...a voice for the marginalized", wrote Sadaf Ahsan, for National Post; literature scholar Lili Pâquet saw such a signifier as resulting from the fallout of her menstrual photographs.

[54] Her work have been the subject of memes online, usually in the form of parody poems mocking Kaur's writing style, their prominence having been compared to a cottage industry.

[141] Tajja Isen disparaged what she regarded as an overly explanatory style, particularly when performed, arguing that Kaur's "belated imposition of rhythm" fails to conceal compositional shortcomings.

[143] In an essay for The Baffler, Soraya Roberts chastised Kaur as disingenuously representative of female South Asian oppression, when she is purportedly chiefly concerned with commodification; Pâquet echoed similar sentiments.

[116][146] In 2019, The New Republic named Kaur "Writer of the Decade", due to her impact on the medium of poetry; this led to a debate on whether the award was deserved, as well as about her work in general.

[147] November 2023, Kaur declined an invitation to attend a Diwali celebration hosted by US Vice President Kamala Harris in the White House, citing the Biden administration's continued support of Israel and its bombardment of Gaza, which she called "the collective punishment of a trapped civilian population".