Kehlani Ashley Parrish was born on April 24, 1995, in Oakland, California. She has described her ethnicity as a mix of "black, white, Native American, Filipino, and Spanish." Her father was African-American and her mother has been described as "mostly white, Spanish and Native American." She was adopted and raised by her aunt when her mother, who was struggling with drug addiction, served time in prison. Kehlani's father, who also suffered from drug addiction, died when she was an infant. During her teenage years, she attended the Oakland School for the Arts, where she initially practiced dance, particularly ballet and modern dance.

Kehlani's singing career effectively began when she started out as a member and lead vocalist for the group called PopLyfe. The band's music was produced by former Tony! Toni! Toné! member, D'Wayne Wiggins. Within two years, the group performed throughout the Bay Area and other cities. In 2011, they auditioned for the sixth season of America's Got Talent, and eventually finished in fourth place. During their final appearance, judge Piers Morgan told Kehlani, "You've got real talent, but I don't think you need the group."

After the end of America's Got Talent, Kehlani left PopLyfe, because of several managerial and contractual disputes. Over six months, she avoided doing anything music related for fear of being sued by the group's management. In 2012 and 2013, Kehlani was effectively homeless, moving from house to house and often sleeping on couches. During her senior year of high school, she moved to Los Angeles, California with no legal guardian. In 2013, Nick Cannon, who had been the host of America's Got Talent during PopLyfe's run, called Kehlani to ask her about being in a rap group. She agreed at first and went to Los Angeles, but, ultimately didn't like the direction of the group and moved back to Oakland. To help with money and food, she decided to begin stealing items from grocery stores for a short time. Months later, Kehlani released her first solo track on SoundCloud, called "ANTISUMMERLUV". Cannon called her back after hearing the song and he set her up with an apartment in LA, along with studio time.

In 2014, the studio time culminated in the release of her first mixtape, called Cloud 19. The mixtape features guest appearances from Kyle Dion. Cannon also sent her to New York City to work with record Producer Jahaan Sweet. The mixtape ranked at twenty-eighth on Complex's list of the "50 Best Albums of 2014," and was also listed among Pitchfork's "Overlooked Mixtapes 2014." A song she released in late 2014, "Till the Morning" was placed by Billboard as one of the "Emerging Picks of the Week" on November 7, 2014. In 2015, Kehlani opened for American Rapper G-Eazy on the second leg of his From the Bay to the Universe tour. On April 28, 2015, she released her second mixtape You Should Be Here. Billboard called it the "year's first great R&B album", when it debuted at number 5 on the US Billboard's Top R&B/Hip-Hop Albums. The project features guest appearances from fellow American Rapper Chance the Rapper, and American singer-songwriter BJ the Chicago Kid. A week after the release, she announced that she had signed a deal to Atlantic Records. In support of the Mixtape, she went on the You Should Be Here tour, which sold out every North American date and select European dates. Throughout 2015, she also received individual plaudits: Complex called her one of the "15 Artists to Watch Out for in 2015" and Rolling Stone named her one of the "10 New Artists You Need to Know." She was also nominated for a 2016 Grammy Award for Best Urban Contemporary Album. Kehlani collaborated with fellow singer-songwriter Zayn on the track, "Wrong" from his debut album Mind of Mine, which was released on March 25, 2016. Her song "Gangsta" was featured on the Soundtrack for the hit movie Suicide Squad, which gave her and her music some beneficial recognition, as it reached number 41 on the Hot 100. On November 26, 2016, she revealed the title of her debut album SweetSexySavage, which was released on Atlantic Records on January 27, 2017.

In January 2016, it was confirmed that Kehlani was in a relationship with star NBA point guard for then the Cleveland Cavaliers, Kyrie Irving. In March 2016, Canadian musician PartyNextDoor posted a picture of Kehlani's hand on Instagram insinuating that they were together. This caused a media controversy across Twitter, in which abuse was tweeted against Kehlani in hundreds of thousands of posts. Irving tweeted that they had broken up before the incident, but this seemed to go unnoticed. The negative media attention caused Kehlani to attempt suicide. Kehlani took to social media to explain that she had not cheated on Irving. In an interview with Power 106, Kehlani discusses her attempted suicide was due to the negative media response as well as her first major heartbreak. She states that her album was therapeutic through her difficult time. During her recovery, she got a tattoo that says “perdida y encontrada” which in English translates to “lost and found”.

After she recuperated, in 2017, she had multiple posts about love for everyone regardless of gender identity, and was motivating fans to accept people's differences and beliefs. While on the SweetSexySavage World Tour she posted pictures of her girlfriend, New Jersey Artist Shaina Negron. On December 5, 2017, Hip-hop Artist Eminem revealed that Kehlani would be collaborating on the song "Nowhere Fast" for his ninth studio album Revival. Kehlani's third annual Tsunami Christmas tour concluded in Santa Ana, California on December 18th, 2017

Kehlani served as an opening act on Demi Lovato's Tell Me You Love Me World Tour in North America, which started on February 26, 2018 and concluded on April 2, 2018. She will then serve as an opening act on Halsey's Hopeless Fountain Kingdom World Tour in Oceania, which will start on April 19, 2018.