Katy Perry and Josh Groban are dating.

The 'I Kissed A Girl' singer has been on a series of intimate dates with the US singer-songwriter, but the pair are keen to keep their fledgling romance out of the spotlight.

A source said: "They've been trying to keep it very low profile."

Perry (24) has previously admitted she is attracted to the 28-year-old singer.

She said: "Who's my most embarrassing crush? I suppose it would have to be Josh Groban. He is actually really cute!"

Perry — who joked she was planning to remain celibate after splitting from Gym Class Heroes rocker Travis McCoy earlier this year — was recently forced to deny she was dating Paris Hilton's ex-boyfriend Benji Madden.

The pair sparked romance rumours after they were spotted together in Las Vegas on Valentine's Day.

Perry wrote on her blog: "It's two pseudo famous people sitting next to each other... doesn't mean we were bumping uglies! You know I don't just do that with anyone!"