Halsey was born and raised in Clark, New Jersey as Ashley Nicolette Frangipane. She is of Italian, Hungarian, and Irish descent on her mother's side and African-American on her father's side. Growing up, Halsey played the violin, viola, and cello until moving onto the acoustic guitar when she was 14. In one of her first interviews, Halsey stated she was diagnosed with bipolar disorder around the age of 16 or 17. When she was 18, Halsey encountered financial trouble and music became a way to pay her rent. She played numerous acoustic shows in different cities under various stage names. She chose "Halsey" as her moniker because it is an anagram of her real name as well as a street in Brooklyn where she spent a lot of time as a teenager. Halsey originally planned on going to college to major in fine arts, but after realizing she could not afford it, she instead enrolled in a community college as a creative writing major.
Halsey's debut studio album, Badlands, was certified 2x Platinum by the RIAA, along with four of its singles. In 2016, they rose to stronger prominence as a featured vocalist on The Chainsmokers' single "Closer", which topped the charts of over fifteen countries and was later certified Diamond in the US. Her second studio album, Hopeless Fountain Kingdom, consisted of more "radio friendly" music than their previous releases. It topped the Billboard 200 and featured two US top-20 singles: "Now or Never" and "Bad at Love". Halsey's third studio album, Manic, released in 2020 has been certified Platinum in the US and its lead single, "Without Me", became her first number-one single on the Billboard Hot 100 as a lead artist.
Halsey has sold 22 million records in the US alone, based on certifications. Their awards and nominations include four Billboard Music Awards, one GLAAD Media Award, a Guinness World Record, a MTV Video Music Award, a Kid’s Choice Award, and a Grammy Award nomination. Halsey is noted for her distinctive singing voice, and their music is usually based on her personal experiences.