The following year, she released her debut commercial mixtape Last Day of Summer (2018), supported by its lead single, "Girls Need Love."

[4] Her debut studio album, Over It (2019) was met with critical and commercial success, peaking at number two on the Billboard 200 chart—briefly breaking the record for the biggest debut streaming week for a female R&B artist—and receiving triple platinum certification by the Recording Industry Association of America (RIAA).

[16] Walker was discovered on Vine by a woman of the same name, who works as the studio manager of an Atlanta-based label called Love Renaissance.

On October 19, 2018, Walker released her debut commercial mixtape, titled Last Day of Summer, supported by the lead single, "Girls Need Love".

[20] On January 25, 2019, Walker released her first EP titled Clear, consisting of four tracks of acoustic recordings.

The song, which contains an interpolation of Destiny's Child's number-one hit "Say My Name", was produced by London on da Track.

[27] On November 17, Walker won her first Soul Train Music Award for Best New Artist, but later received backlash from fans for her short speech and was accused of faking her social anxiety.

[32] On October 14, Walker won the Billboard Music Award for the Best Female R&B Artist at the 2020 ceremony, beating out Beyoncé and Lizzo.

[citation needed] On November 23, she released a repackaged version of the Over It album, titled Over It (Complete Edition).

On November 29, Walker and Ari Lennox performed the song "Unloyal" together at the 2021 Soul Train Music Awards.

[41] These updated versions, which included a solo acoustic performance from Walker, also featured artists like Victoria Monet, Tyla, and Tink.

[49] Walker has said that she draws inspiration from Amy Winehouse, Jimi Hendrix, Donell Jones and Erykah Badu.

Walker has also cited Lauryn Hill and D'Angelo as inspirations for her to experiment and explore new sounds within the R&B and neo soul genres.