News of the split was reported by TMZ on Tuesday (local time), almost a month to the day after Fox revealed they were expecting their first child together.
The outlet reported the couple broke up after Fox, 38, allegedly discovered something untoward on the rapper’s phone as they were holidaying in Vail, Colorado over Thanksgiving, causing her to leave early.
It’s understood the split happened just two weeks after the actress announced she and Kelly, real name Colson Baker, were pregnant.
On November 11, the Jennifer’s Body actress shared a stylised shot on Instagram of her naked body dripping with what appeared to be black paint. A second black-and-white snap showed a positive pregnancy test with the word “Yes” clearly displayed.
“Nothing is ever really lost. Welcome back,” Fox captioned the post, which has since been removed from her Instagram.
Kelly addressed the news on his social media, writing via X: “Isolating myself in the desert next week to restart this album from scratch.”
“When inspiration flows through me unblocked, we will reach the destination in no time. Don’t worry. After all, I’m about to be a dad again!”
Both Fox and Kelly, 34, have children from previous relationships. Fox shares her sons Noah, 12, Bodhi, 10, and Journey, 8, with ex-husband Brian Austin Green, while Kelly has a 15-year-old daughter, Casie, with ex-partner Emma Cannon.
Fox, who split from Green in May 2020 after nearly 10 years of marriage, first started dating Kelly that year after the pair worked together on the film Midnight in the Switchgrass.
The two had previously suffered a miscarriage, an experience Fox wrote candidly about last year in her poetry book, Pretty Boys are Poisonous.
“I want to hold your hand / hear your laugh, but now / I have to say / goodbye,” she wrote, adding elsewhere in the book: “I will pay any price. Tell me please / what is the ransom / for her soul?”
During an interview on Good Morning America at the time, Fox revealed she had “never been through anything like that before”.
“It was very difficult for both of us,” she explained. “And it sent us on a very wild journey together and separately, and together and apart, and together and apart, and together and apart, trying to navigate, ‘What does this mean? Why did this happen?’”
The couple have been plagued by break-up rumours. Early last year, it was reported the pair had parted ways following “a big fight”: they later reconciled and were frequently pictured together throughout the latter half of 2023.
In March, Fox confirmed they had called off their engagement – but weeks later they appeared to be back together, as they were photographed cuddling at parties and festivals.