The Mirror claims reps for the superstar confirmed engagement reports, despite 45-year-old Mariah and James, 48, having yet to comment on the news.
It’s thought James – who is Australia’s fourth richest man – gathered some of Mariah’s closest friends before getting down on one knee in New York this week.
A source told E! News: “It’s crazy how perfect they are together, they both know it and couldn’t be happier.”
Mother-of-two Mariah and businessman James met in 2014 but didn’t get together until June 2015, before going public with their relationship in October that year.
Although the Vision of Love singer is keeping the rock under wraps for now, it’s been claimed that it is a 35-carat diamond and ‘what can only be described as the most breathtaking engagement ring’.
Mariah has been married twice before, to music mogul Tommy Mottola in June 1993 and to presenter Nick Cannon in April 2008.
She and Nick, 35, share four-year-old twins Moroccan and Monroe, and filed for divorce in December 2014.
James has also been married twice before and has three children.
Congratulations to Mariah and James!