The 33-year-old music sensation — who is dating Travis Kelce — attended the gathering in a slightly oversized navy sweater and a pleated, plaid mini skirt.
The Eras artist looked every bit the star as she wore a pair of black shades and swiped her pout with peach-toned lipstick.
Complementing her leggy display during the cloudy day was a pair of black combat boots.
She was seen exiting a venue in Tribeca with Blake, 36, and Ryan, 46.
Celebration: Taylor Swift was a guest at close friend Blake Lively and her husband Ryan Reynolds’ daughter Inez’s birthday party on Saturday in New York City
The singer-songwriter’s golden blonde locks were arranged in fluffy, natural-looking curls that fell down her back.
Her voluminous and bouncy locks were anchored by face-framing bangs.
Taylor rocked a dark manicure as her friends accompanied her out of the event.
Emily Blunt was also on the scene as she took one of her and husband John Krasinski’s young daughters to the get together.
The actress wore a long purple cardigan with multicolor bottoms and she carried a shiny black purse.
Bradley Cooper was another famous face who attended the party as he held his and ex-girlfriend Irina Shayk’s daughter Lea’s hand.
The Silver Linings Playbook star was in full-on dad mode as he rocked a button-up navy shirt, dark jeans, and sneakers.
He also wore several accessories — a black baseball cap, round sunglasses, and a black backpack.
Invitee: Emily Blunt was spotted escorting her and husband John Krasinski’s daughter
Friend: Bradley Cooper brought his and ex-girlfriend Irina Shayk’s daughter to the soiree
Meanwhile, Reynolds looked dapper as he showed off his sense of fall fashion.
He wore a navy windbreaker jacket over a light blue and white plaid shirt.
The father-of-four added a pair of slim-fitting chino pants, and he stepped out in white sneakers.
He looked smart in a pair of rectangular, black-rimmed eyeglasses and he sported a full beard.
His short, brown hair was neatly cut over his ears and the top was wispy.
Blake commanded attention as she modeled a flowy dress and cropped jacket, each piece with different patterns.
She maintained a cream and red color palette, coordinating the look with matching loafers.
Her lengthy, dirty blonde locks were worn in her usual loose style that was arranged with a deep side part.
Great mood: Swift appeared in good spirits as she flashed a soft, toothy smile
Fashion-forward: Blake wowed as she mixed patterns and modeled a red and white color palette
Accessory: Taylor carried an orange-toned purse with a silver chain strap over her shoulder
Glam: The Eras pop star looked every bit the star as she wore a pair of black shades and swiped her pout with peach-toned lipstick
Leftover treat: A cake was carried to the car Taylor was headed toward
Swift and Lively have a long and close friendship that dates back to 2015.
And earlier this year Taylor made a special gesture to her Lively’s daughters Inez and James, 8, during the Philadelphia stop of her Eras Tour.
Blake brought along her two eldest children for the night of live music and Taylor took a moment to acknowledge the special guests as she mouthed what appeared to be ‘Hi, James! Hi, Inez!’ at one point.
The sweet moment was captured by fans who later posted it to social media, along with a clip of Swift exiting the stage with the trio in tow.