Mariah Carey engaged to Australian billionaire James Packer

US singer Mariah Carey and Aussie billionaire James Packer. Photo / AFP

Mariah Carey and James Packer are engaged.

The Australian billionaire and the Without You hitmaker may have only been dating for less than 12 months but they are set to tie the knot after he reportedly got down on one knee in her hometown yesterday.

A source told E! News: "They fell head over heels in love with one another. It's crazy how perfect they are together, they both know it and couldn't be happier.

"As soon as their friendship turned romantic, they have wanted to spend every moment together. They have a connection that is unparalleled; it's been a very beautiful experience for them both. If you spend even five minutes with them, you can't help but believe in true love.

"They are just very cute together, they like doing sweet things for one another. They want to make each other happy."

Meanwhile, James - who is said to have splashed out on a 35 carat diamond engagement ring - was recently praised by his bride-to-be.

She gushed: "He's a great person. He's just an incredible guy. He really is a good person, and that's hard to find.

"I think anybody that's a friend of his would say the same thing, if not more, so I can't say enough nice things about him. He's just a spectacular guy."

- Bang! Showbiz