The presenter, 28, was rumoured to be dating the One Direction hunk, 20, last year after they appeared to be leaving the same building the morning after a night out, but she's confessed she was never romantically involved with him because he's far too young for her.
She told heat magazine: ''I was never seeing Niall. He's a child. The most embarrassing thing about that is that people thought we were together.
''I love Niall, he's lovely. But I'm 28. He's a boy. And he kind of looks like my little brother. So, no.''
Laura - who is reportedly dating 'Scream (Funk Up My Life)' hitmaker Paolo Nutini - has been signed up to present the Eurovision song contest's semi final with BBC Radio 1 presenter Scott Mills.
She is also reportedly taking over from Caroline Flack as the host of 'The Xtra Factor', but she claims she hasn't been offered the job.
She explained: ''My mother actually called me up and was like, 'You didn't tell me you were doing 'The Xtra Factor'!' But listen, I've been in LA for a week, so I have no idea what's going on.''
'Wilson', starring both Dern and Harrelson, is released in U.S. cinemas on March 24th.
At just 13, Robert Irwin is continuing his father’s legacy and he’s just as enthusiastic about animals as his dad.
Madonna adopted twins Esther and Stella from Malawi earlier this month.