Originally born in Birmingham to Jamaican parents, Allen moved to the Netherlands when she was five years old. Her family remained in Holland for nine years before moving to Clapton, East London when she was 14. As Allen grew older she knew she wanted to pursue music, taking on the initial strategy of covering other artists' work and spinning it in new directions; the first two efforts that gained traction came in 2015, when Allen covered Wretch 32's "Six Words" and Section Boyz's "Lock Arff." As Allen became more popular, she collaborated with a number of prominent artists including Lethal Bizzle, Sneakbo, Jeremih, and Wretch 32 on his 2016 album Growing Over Life. That year also saw the release of her debut mixtape, Real Ting, which featured Jeremih returning the favor as a guest artist. As 2016 drew to a close, Stefflon Don was highlighted on the BBC's Sound of 2017 list.
She kicked off 2018 with the release of the Hurtin' Me EP (Polydor), which featured "Instruction" with Jax Jones and Demi Lovato, as well as the U.K. Top Ten title track, and in 2019 she issued the single "Phone Down," a collaboration with rapper Lil Baby. The following year saw the release of the Afrobeats-tinged track "Can't Let You Go." 2021 singles included "Toxic Love" and "The Don." "Bun Fi Bun," "Juice," and "Like That" all appeared in 2022, as well as "The One" and "Daily Duppy (Dem Dead)." ~ Liam Martin & Paul Simpson, Rovi