"I've never been happier. I am just so, so in love. For the first year, we've been working out how to be together because our jobs are so crazy and all over the place," the Daily Telegraph quoted her as having told the Daily Mirror newspaper in the U.K. She said: "But I know he's The One. That's all I can say - he is The One. I adore my boyfriend."
She apparently met Smith, a former British rugby league player, while on a holiday in Spain a year ago.
"We've just had our one-year anniversary. I surprised him and flew out from London to Sydney for his birthday," the beauty who is a judge on the Seven Network's Australia's Got Talent and Britain's X Factor added.
"He had a big fashion show there and it took a month of planning. It's hard to surprise someone when there are people reporting where you are. But it worked - I did surprise him. It was just incredible. And then to go into midnight when it was his birthday and our anniversary was awesome - he got me a beautiful necklace," she added.
The couple have even discussed marriage, but they intend to take it slow.
"I guess we've talked about marriage but we're trying to take things slowly. I think it's a guy's thing to propose, although I haven't really thought about the details. I guess at my age I have to start thinking about babies at some time. But to be honest, I'm just enjoying being so wildly in love and being so happy.
"I honestly never thought this would happen to me. So I haven't been thinking too far ahead, just enjoying every day as it happens. But it will come when it comes."
Minogue has divorced from Australian actor Julian Mcmahon fame, apart from being engaged to former Formula 1 racing driver Jacques Villeneuve in the past.