The 22-year-old singer has been revealed to be dating the 18-year-old pop star after they were spotted holding hands backstage at 'The X Factor' USA last week but the blossoming relationship has angered some One Direction fans who have taken to twitter to post vile messages against her.
One user under the name of Patrick Bateman, the serial killer character from the film 'American Psycho', posted a chilling threat: "You're a f***ing ugly bitch. I want to stab you to death and play around with your blood. (sic)"
Another user branded her a paedophile, tweeting: "Taylor Swift is a peado. She's dating Harry Styles (sic)"
Mario Lopez, who presents 'The X Factor' USA, appeared on American radio station MY FM to confirm the rumours shortly after Taylor's appearance on the show last Thursday.
He revealed: "Taylor Swift was the special guest performer and here is a little inside scoop for you. During rehearsals Harry from One Direction came over and slapped me on the back, and said, 'Hey Mario how you doing?' And I said 'What are you doing here?' and he sort of pointed towards Taylor.
"Later I saw them walking 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."
The pair briefly dated back in April but parted ways after photos of Harry kissing American model Emma Ostilly in Australia arose and this time round Harry wants to take things slowly in the relationship.
An insider revealed: "Taylor and Harry have been quietly seeing each other again. When Taylor dates someone she jumps in full force, but Harry is being a little more cautious this time around."