It's understood that the One Direction star has already moved out of the lavish £5 million (NZ$9.7 million) mansion he shared with Cheryl and Bear in leafy Surrey.
According to The Sun, the couple had mutually agreed to separate a fortnight ago following months of speculation regarding the state of their relationship.
A source told the publication: "Cheryl and Liam worked really hard on their relationship – they had troubles earlier this year and were able to get through them.
"But they're in different stages of their lives and, after a lot of careful thought, came to a decision that it's best for everyone if they do go their separate ways.
"He still cares for her and she cares for him. They still have an ongoing relationship together. They have a baby together."
The announcement comes little more than 24-hours after Cheryl celebrated her 35th birthday, a milestone Liam failed to acknowledge on social media despite flying back to the United Kingdom earlier that day.
Cheryl and Liam, who welcomed Bear in March 2017, have not been seen together publicly in four months, with February's BRIT Awards the last time fans saw them walking the carpet as a couple.
Just last week Liam spoke fondly of the former Girls Aloud singer while admitting that she had made the first move by "tickling him" when they reunited on The X Factor in 2014.
"Chez kind of made the first move on me if I'm honest. She tickled my hair. I thought 'oh you're into this'. And now look... a few years later..." he told Radio 1 Breakfast Show host Nick Grimshaw.