It's knocked Adele's 25 from the top spot.
The former One Direction band member's first single "Pillowtalk" also went straight to number one in February.
He told the Offcial Charts Company: "I can't believe that I have managed to achieve this as a solo artist.
"I am very proud coming from Bradford achieving this in my home country.
"It's mind-blowing to me. I don't take the support I have received for granted. My life at 23 could have been very different."
Enter a name and e-mail address and we will e-mail this website link too them.