The 25-year-old model and the 27-year-old musician are expecting their first child together, a source tells ET. It's been almost five years since romance rumors between the two first surfaced and went on to date on-and-off since 2015.
The two had their fair share of ups and downs -- including two breakups, one Vogue cover, reconciliations and many more -- but appear to be stronger than ever.
As the two begin to expand their family together, ET's taking a look at Hadid and Malik's love story from first dates to baby on the way.
Fans got a look at their insane chemistry when Hadid starred in Malik's music video for his debut single, "Pillowtalk." They then engaged in a flirty back-and-forth on Twitter that fans couldn't help but notice.
During an interview with Zach Sang & the Gang, the former One Direction member seemingly confirmed that Hadid was his girlfriend. When asked, "was it cool to have your girlfriend in the video?" he replied "Uh, yeah that was cool. That was something different and, yeah, we enjoyed it. That was fun, we had a lot of fun on set."
The couple, dubbed Zigi, posed together in Naples, Italy, for a glamorous photoshoot by famed photographer Mario Testino for the May issue of Vogue.
The two made their red carpet debut as a couple at the Met Gala. The year's theme was Manus x Machina: Fashion in an Age of Technology.
Things continued to go well for the pair and even landed their own Vogue cover. The pair posed for the August issue of the fashion publication, with Hadid sharing the most romantic thing her boyfriend had done for her. "A couple of years ago on Valentine's Day, we went on a boat trip, and that was really nice," she said at the time.
Hadid and Malik split for the first time. After more than two years of dating, the two decided to call it quits. Malik confirmed the upsetting news via Twitter, sharing a note that was seemingly written using the Notes app on his iPhone.
"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 friend," the "Pillowtalk" singer shared. "She has such an incredible soul. 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. We love you all."
Hadid shared her own statement, echoing Malik's amicable words.
"Breakup statements often seem impersonal because there is really no way to put into words what two people experience together over a few years," she explained. "Not only in the relationship, but in life in general. 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."
Hadid clapped back at an account that claimed her relationship with the singer was fake.
“Seems like u guys tag me in a new post every day… pls stop.. it’s just negative, I really have no hard feelings towards you I just know what a beautiful world there is to go out and live in instead of trying to dissect a relationship between two people that you don’t even know and that you do not see 99% of,” Gigi wrote in part on a post that called out the fact that Malik didn't follow her on Instagram. “For someone who is virtually inactive on the app, I don’t need his follow- my eyes are tattooed to his chest.”
The two spend the Muslim holiday of Eid together, where Hadid enjoyed quality time with Malik's family.
Oct 21 was Hadid's last Instagram post with Malik before their second split. "Flyin home to my happy place," she wrote alongside a picture of the two cuddling.
Zigi splits for a second time. After fans began to speculate that they were no longer together, amid their lack of social media and outings, a source told ET on Jan. 3 that the two had indeed broken up.
"Gigi and Zayn have broken up, but not because they don’t love one another," the source said at the time. "After trying for a long time, the couple just couldn’t make it work. Zayn has been dealing with personal things for a while and Gigi has become a comfort blanket for him."
"Gigi will always support him but she has realized only Zayn can help Zayn," the source continued.
However, a couple weeks later, Hadid was spotted leaving her ex's NYC apartment.
Fans only began thinking they were back together when Malik tweeted, "@GiGiHadid love you," on March 2. The model never replied.
The "I Don't Wanna Live Forever" singer quickly shot back at haters, telling critics to leave his ex-girlfriend "the f**k alone," after they assumed some of his previous tweets were about her.
"My tweet was not about @GigiHadid so leave her the f**k alone," Malik, 26, wrote on Twitter on April 4. "She is the most amazing woman I've ever known. And does nothing but love and support me when lord knows I don’t deserve it."
The former couple began to "talk," but not because they were hoping to rekindle their romance, a source told ET.
"The two have continued to talk and support one another since their breakup, but they're not dating or talking like that anymore, just friends," the source said. "Zayn and Gigi have a special relationship, respect one another and want what’s best for one another. They don’t know what the future holds, but for now it’s not them as a couple."
The two held each other close on their way back to Hadid's apartment.
The blonde beauty confirmed that she and Malik were back together when she wrote about her "valentine." The model shared a picture of Malik, captioning it, "HEY VALENTINE. Z on the farm ♡ Dec 2019."
Hadid had Malik right by her side for her 25th birthday on April 23. The birthday girl shared a sweet boomerang of her birthday celebration with sister Bella Hadid and boyfriend. The post showed Malik sandwiched between the sisters in an embrace, with Hadid proudly holding up balloons for her special day.
"Gigi and Zayn are expecting their first child together and the couple is very excited!" ET's source said. "Gigi has kept the secret close to her family and friends for a while, as she’s only a few months along. Once Gigi and Zayn got back together at the end of last year, it was like they never skipped a beat and knew what they had was special. The couple and their families are overjoyed."