The couple began dating earlier this year after 25-year-old Halsey sent the British star a direct message with her phone number.
The pair took their romance to the stage at the 2019 iHeartRadio Wango Tango concert in June with a steamy performance of their "11 Minutes" collaboration.
However, fans speculated the couple had split in recent weeks and, after the "Without Me" star and rumoured beau Evan Peters made their red carpet debut on Saturday, October 26 at the party for television drama "American Horror Story" 100th episode, the singer took to Twitter to speak out on the breakup.
"Sometimes. People just break up. It doesn't mean someone cheated or something bad happened or someone f***d up. Sometimes. It just happens," she penned, suggesting the separation was amicable. "Because life Is constantly changing. And adults stay friends and move on."
While it remains unknown when the former couple split, Halsey and Evan were first linked in late September when they were spotted holding hands at the Six Flags Magic Mountain theme park in California.