Happy birthday, Caitlyn!
Caitlyn Jenner got a birthday celebration a day early!
The former Olympian rang in her 66th birthday on Tuesday with a birthday lunch at The Villa in Woodland Hills, California, where she was joined by Kim Kardashian, Kylie Jenner, Kourtney Kardashian, and Penelope Disick. Kendall Jenner and Khloe Kardashian were not spotted at Caitlyn’s birthday get-together, which lasted about an hour and a half.
WATCH: Caitlyn Jenner Wears Same Dress That Kate Middleton Wore for Her 2010 Engagement Pics
An eyewitness tells ET that "Kourtney, Kim and Penelope arrived together and Kylie arrived on her own," adding that everyone "seemed very upbeat and ready to have a birthday lunch a day early." Two black boxes (perhaps bearing gifts!) were also brought inside the restaurant.
Another source tells ET that the group arrived at the restaurant at around 1 p.m. “The staff really tried to give them their privacy,” the source adds.
WATCH: Caitlyn Jenner Desires a 'Normal Relationship' and for a Man to Treat Her Like a Woman
Meanwhile, Kim's baby bump was on full display in one of her characteristic nude-color looks.
Kylie captured the celebration on Instagram, writing, "Early birthday lunch with @caitlynjenner Happy birthday dad what an amazing year for you."
WATCH: Caitlyn Jenner Reveals If She Ever Misses Being Bruce
The reality star's look for Caitlyn's pre-big day was a show-stopping, black Alexander Wang dress.
WATCH: Kylie Jenner and Tyga Adopt a Puppy Reportedly Worth $50,000
Last week, Caitlyn wished Kim a happy birthday, using this adorable throwback photo from earlier days.
WATCH: Kylie Jenner Strips Down for Super Sexy Desert Photoshoot
This is Caitlyn's first birthday since her Vanity Fair introduction to the world back in June.
"Bruce always had to tell a lie. He was always living that lie. Every day he always had a secret, from morning to night," Caitlyn confessed behind the scenes at her Vanity Fair photo shoot at the time. "Caitlyn doesn't have any secrets. As soon as the Vanity Fair cover comes out, I'm free."
WATCH: Kylie Jenner Makes 'Weird' Revelation, Says She Is, Like, So Over Big Lips
Since then, Caitlyn has turned into not only a role model and transgender icon, but oftentimes, a style icon too! Last week, the I Am Cait star stepped out while channeling none other than the Duchess of Cambridge herself, Kate Middleton.
Happy birthday, Caitlyn!
Watch the video below.