The American model shared a sweet moment with the 24-year-old British singer after mom Yolanda Hadid and sister Bella Hadid posted throwback photos for her birthday Sunday.
Gigi was all smiles in a kiss picture with Malik that received over 2.6 million likes on Instagram. The post also showed her birthday cake, which read "Happy Birthday Gigi" and featured an icing flower.
Malik also kissed Gigi in a snapshot on his account that received over 1.3 million likes. He captioned the photo, "happy birthday to my everything."
Gigi and Malik were first linked in November 2015, and made their red carpet debut as a couple at the Met gala in May. The model recounted her first date with Malik on The Ellen DeGeneres Show in February.
"We played it cool for, like, 10 minutes, and then I was like, 'You're really cute,'" she told DeGeneres. "We connected really quickly. We kind of had the same sense of humor and started sharing videos."
Gigi is the eldest child of Yolanda, a Real Housewives of Beverly Hills alum, and Mohamed Hadid, a real estate developer. Yolanda and Bella, a 20-year-old model, wished Gigi happy birthday with a series of throwback photos.
"Happy birthday to my sweet Angel...... I pray that each day Love, Health and Happiness will come your way. I'am so proud of the human being that you are and grateful to experience this journey of life with you everyday through the good and the bad. May all your dreams come true this coming year and let it be filled with joy and laughter #HappyBirthday #MyLove #22 #ILoveYou #AlwaysAndForever," Yolanda wrote.
"Happy birthday to my best friend FOR [expletive] LIFE!!!!!!!! My role model! My person. I feel so lucky every day to call you my sister. I didn't know anyone could be so generous, smart, funny, talented, hard working, artistic, loving, respectful AND beautiful all at the same damn time!!!" Bella added. "You are my other half & I don't know what I would ever do without you. I love you with all of my heart Squeegee. @gigihadid."