The 25-year-old British singer and 22-year-old American model confirmed their breakup Tuesday on Twitter following reports of their split.
"Gigi and I had an incredibly meaningful, loving and fun relationship and I have a huge amount of respect and adoration for Gigi as a woman and a friend. She has such an incredible soul," Malik wrote.
"I'm grateful to all of our fans for respecting this difficult decision and our privacy at this time, we wish this news could have come from us first," he added. "We love you all. xZ."
Hadid said on her own account that she's "forever grateful" for her time with the former One Direction singer.
"Breakup statements often seem impersonal because there is really no way to put into words what two people experience together over a few years.. not only in the relationship, but in life in general," the model said.
"I'm forever grateful for the love, time, and life lessons that Z and I shared. I want nothing but the best for him and will continue to support him as a friend that I have immense respect and love for," she added. "As for the future, whatever's meant to be will always be. xG."
Malik and Hadid were first linked in November 2015, and made their red carpet debut as a couple at the Met Gala the next year. The Sun had reported the couple's split Tuesday morning.
"Sadly Zayn and Gigi have separated," a source said. "They are no longer a couple but they do remain close and are supportive of each other ... They have crazy work schedules that would put pressure on any relationship."