"My life with One Direction has been more than I could ever have imagined. But, after five years, I feel like it is now the right time for me to leave the band," he said in a statement posted on the band's Facebook page. "I'd like to apologize to the fans if I've let anyone down, but I have to do what feels right in my heart."
"I am leaving because I want to be a normal 22-year-old who is able to relax and have some private time out of the spotlight. I know I have four friends for life in Louis, Liam, Harry and Niall. I know they will continue to be the best band in the world," he added.
The news comes a week after he left the group's world tour, citing stress. He also fought back on Twitter recently at rumors of trouble in his relationship with fiancee Perrie Edwards of the band Little Mix.
The remaining four members of One Direction -- Niall Horan, Harry Styles, Liam Payne and Louis Tomlinson -- will continue on with the tour and working on their fifth album, the announcement said.
"We're really sad to see Zayn go, but we totally respect his decision and send him all our love for the future," they said. "The past five years have been beyond amazing, we've gone through so much together, so we will always be friends. The four of us will now continue. We're looking forward to recording the new album and seeing all the fans on the next stage of the world tour."
Simon Cowell, who brought the quintet together as a group on the seventh season of Britain's "The X Factor," also released a statement thanking Malik and addressing the future of the band without him.
"I would like to say thank you to Zayn for everything he has done for One Direction. Since I first met Zayn in 2010, I have grown very, very fond -- and immensely proud -- of him," Cowell said. "I have seen him grow in confidence and I am truly sorry to see him leave. As for One Direction, fans can rest assured that Niall, Liam, Harry and Louis are hugely excited about the future of the band."