The 22-year-old "Drag Me Down" hitmaker announced the news on Twitter along with a picture of a music CD's dummy.
"Happy to have signed to @CapitolUK. They have an amazing history of artists, I hope I can follow in their footsteps," he wrote.
The singer had to face criticism soon after the post, to which he clarified that, "One direction will always be my home and family but I'm very excited to see what this chapter brings.