Last night, Gigi Hadid and her crew of It Girls combined Americana cool with Parisian elegance in honor of the model's big 2-4. The theme of the evening? Denim. The locale? L'Avenue at Saks, the NYC outpost of the French hot spot. Certainly a stylish choice for such a stylish birthday girl.

Rocking a simple white baby tee, along with blue jeans embroidered with the number "24," Gigi danced the night away to throwback hits, blew out the sparklers on a giant "24" cake dotted with macarons, and took a few turns with her friends in one of those famous flawless-skin photo booths.

She was joined, of course, by her family, including mom Yolanda, dad Mohamed, brother Anwar, and sisters Bella and Alana, along with a few A-list besties like Ashley Graham, Olivia Culpo, Hailee Steinfeld, and Helena Christensen. Everyone enthusiastically stuck to the James Dean-approved theme - except for Taylor Swift, who arrived in an oversized houndstooth blazer and floral frock. OK, Tay.

Guests enjoyed overflowing plates of frites and specialty cocktails throughout the evening, including a passionfruit "Taurus Juice," and a gin-and-green apple concoction simply called "For Yolanda." Aww! Even when it's her day, Gigi never forgets to pay tribute to mama. 

Click through for an inside look at the glamorous bash!