The 18-year-old was spotted in New York with American country singing sensation Taylor Swift (22), who he has been dating for the past month.
In their first public appearance since they started dating, the smitten pair were spotted walking hand in hand in New York's Central Park.
Harry was in New York with his chart-topping band ahead of their performance at Madison Square Gardens last night.
He and Taylor have been enjoying quality time with one another while also hanging out with Harry's band mates and their pal Ed Sheeran, who has recorded a duet with Taylor.
Harry was seen laughing and joking with the blonde beauty yesterday and, according to sources, he was the perfect gentleman throughout.
One said: "Harry kept making sure Taylor was warm enough. You could tell they were totally smitten."
And he was not the only band member enjoying some romance in the city.
Despite enjoying a string of dates with X Factor winner Leona Lewis (27), Liam Payne (19) has reportedly rekindled his romance with Danielle Peazer (24).
The couple split up back in August, but dancer Danielle was spotted holding hands with Liam outside a jewellery shop on New York's Fifth Avenue yesterday afternoon.
Meanwhile, the boys were also joined in New York by Little Mix star Perrie Edwards, who flew out to spend time with her boyfriend Zayn Malik (19).
Last week Harry said of Taylor: "She honestly couldn't be a sweeter person. She's genuinely nice and extremely talented, and she deserves everything she has."
Taylor's afternoon of romance with Harry came just before she appeared at a charity gala in New York alongside her ex Jack Kennedy's family.