Swift, 22, was spotted holding hands with Styles on the backstage of 'The X Factor' where she was rehearsing for her performance.
Another hint was given by the show's host Mario Lopez, who said on his radio show that he saw Swift and Styles holding hands after her performance.
"Taylor Swift was the special guest performer, and (here's) a little inside scoop for you. During rehearsals, Harry from One Direction came and slapped me on the back, and said, 'Hey, Mario, how ya doing?' And I said, 'What are you doing here?' And he sort of (pointed) toward Taylor," Lopez said on his radio show.
Lopez said the two "walked off hand in hand... So Taylor Swift and Harry from One Direction -- you heard it here first. (They're) officially hanging out, I can say that much," Lopez said.
Harry, 18, had met Swift at Choice Awards in March where she danced on band's song 'What makes you beautiful'.
However, a planned date after the MTV Awards in LA was cancelled due to his travelling schedule.
Swift has dated a string of popular men including Jake Gyllenhaal, Joe Jonas, Taylor Lautner, John Mayer and Cory Monteith in the past. The singer is notorious for blasting her former lovers in the lyrics of her songs.
