Gigi and Bella Hadid’s secret half-sister has been revealed.

Aydan Nix, 23, is a fashion designer, stylist and aspiring influencer who bears a strong resemblance to the models.

She’s the daughter of their father, Mohamed Hadid, and a woman named Terri Hatfield Dull, with whom the real estate developer had a brief romance following his 2001 divorce from Yolanda Hadid.

“Over 20 years ago, our dad, while single, had a brief relationship that led to a pregnancy,” Gigi, 30, and Bella, 28, told the Daily Mail in a statement Thursday.

“Aydan was born and raised in Florida, growing up with the man she lovingly knew as her father until his sudden passing when she was 19.”

According to Gigi and Bella, Nix then “decided to take a genetic test out of curiosity,” which led her to discover “a biological connection” to the cover girls.

The trio “first connected in late 2023,” at which point the Hadids “embraced Aydan with open arms.”

Nix — who recently graduated from the Parsons School of Design in Manhattan — has “spent time” with all of the Hadids, including Mohamed, 78, though he has not yet publicly acknowledged her existence.

“We’ve cherished this unexpected and beautiful addition to our family,” Gigi and Bella gushed.

“As siblings, we’ve had many open and loving conversations — with Aydan included — about how to support and protect her.”

The superstars made sure to note that Nix and her family “value their privacy” and asked the public to “honor her wish and right to her anonymity as she continues her life as a young woman in New York.”

According to the Daily Mail, Mohamed’s fling with Dull — who has worked as a mortgage loan originator — ended shortly before she discovered she was pregnant.

Mohamed reportedly always knew about Nix, with whom he is “cordial and pleasant,” but has not provided financial support.

“There’s mutual respect,” a family source told the outlet, “but there’s also discretion.”

In addition to Gigi and Bella, Mohamed and Yolanda, 61, share son Anwar Hadid, 25. The Nazareth native is also dad to daughters Marielle Hadid, 44, and Alana Hadid, 39, whose mother is his first wife, Mary Butler.

As for Nix, she was an honor student and cheerleader at a prep school in Orlando but also held down a summer job delivering Domino’s Pizza.

After graduating from high school, Nix moved to the Big Apple to pursue a career in fashion. During her time at Parsons, she interned with stylists and photographers and worked as a commissioned sales associate at the vintage clothing store Harley’s.

Mohamed was reportedly expected to attend her college graduation earlier this month but canceled about a week beforehand.