Apple! Boomer! Shiloh! See Which Celeb Babies Celebrate Their Birthdays in May

MAXWELL JOHNSON

Jessica Simpson's little lady Maxwell Drew rings in her fifth year May 1 — and 2017 involved a mermaid party.

"Happy Birthday to our fairytale princess," Simpson captioned a family snap including herself, Maxi, husband Eric Johnson and son Ace Knute, 3½.

HELENE "LENI" SAMUEL

Seal and Heidi Klum's oldest child Leni becomes a teenager on May 4. The amicable exes also share daughter Lou Sulola, 7½, Johan Riley Fyodor Taiwo, 10, and Henry Günther Ademola Dashtu, 11.

BOOMER PHELPS

Potential future swimmer extraordinaire Boomer Robert is only celebrating his first birthday May 5.

But in a snap shared by dad Michael Phelps and mom Nicole Johnson Phelps, he's already sporting some adorable facial hair, thanks to a novelty pacifier.

GREYSON MATHEWS

Sharing an (exact!) birthday with baby Boomer is Jenni "JWoww" Farley and Roger Mathews' younger child Greyson Valor, who also turns 1!

"My heart doubled in size and it's all because of you. You will forever be little baby, my 'bubby,' " Farley captioned an Instagram photo gallery to mark her baby boy's big day. "Happy birthday Greyson."

EVELYN WILLIS

The youngest of Bruce Willis' five daughters, Evelyn Penn, is another Cinco de Mayo celeb-kid birthday.

"Happy 3rd Birthday to this little love bug. My ray of light," mom Emma Heming Willis wrote alongside a snap of the mother-daughter duo (the couple's older daughter, Mabel Ray, is 5).

JAXON CUTLER

Kristin Cavallari and Jay Cutler's son Jaxon Wyatt turns 3 on May 7 — and the parents of three have some pretty fun party plans up their sleeve.

"It's at this place called The Blast Zone and they have the big trampolines and the foam pit and the kids can just run around," The Hills alum told PEOPLE.

On his big day, Cavallari shared an oceanside photo of her little guy, captioning it, "Happy 3rd birthday to my wild child, Jaxon. You brighten up our lives little man 💙."

NOAH MAZUR

"Happy 5th ... 🎈🎈🎈🎈🎈 #NoahPhoenix #birthdayboy#mamasboy 🎉," Alessandra Ambrosio captioned a May 7 snap of herself and her younger child Noah Phoenix at his Ghostbusters-themed birthday party.

The model and her fiancé Jamie Mazur are also parents to daughter Anja Louise, 8½.

LAIRD STONE

Sharon Stone's middle son Laird Vonne is officially a preteen this month, celebrating his big day alongside his mom and brothers Quinn Kelly, 10, and Roan Joseph, 16.

"Happy 12th birthday Laird! #family #love 🎉," Stone wrote alongside a family photo on May 9.

RYAN ROSENBERG

Ryan Ava Erhard — the adorable little girl of Haylie Duff and fiancé Matt Rosenberg — is 2 years old as of May 11.

"Happiest of birthdays to our little music loving princess 🌟 💫 You are the sweetest little girl & we are so proud of you everyday! #ThisIsTwo ✌️," Duff captioned a royal snap of her daughter.

APPLE MARTIN

Family comes first for amicable co-parents Gwyneth Paltrow and Chris Martin, whose older child, daughter Apple Blythe Alison, enters her teenage years May 14.

"Happy 13th birthday, you gorgeous human," Paltrow captioned a photo of Apple on her big day — which falls, appropriately, on Mother's Day this year.

"You light up every room, my heart, the world. You. Are. Everything. I love you, schnapps. #🍎"

ALIJAH BASKETT

The younger child of Hank and Kendra Wilkinson Baskett, Alijah Mary, is 3 as of May 16. (The spouses also share son Hank Randall IV, 7.)

"Happy 3rd birthday to my big girl," the proud mom captioned a beachside Instagram photo.

"I remember holding her in my arms right now in the hospital. She's a free spirit just like me n I'm so proud of her. 🎂"

STORY GOLDBERG

"With my sweet baby Story! Happy first birthday my love 💙 xoxo," Soleil Moon Frye captioned a snap of herself and her youngest child in front of his animal-themed cake to celebrate his big day, which was May 16.

FUTURE WILBURN

Future Zahir has a lot to celebrate on May 19 — he turns 3!

The son of Ciara and rapper Future celebrated the milestone over his birthday weekend with a Hotel Transylvania 2-themed bash, complete with face painting, balloon motorcycles and a three-tier themed cake.

"Surrounded By So Much Love! We Love You Sooo Much. #Birthday Love. 🎈❤️🎂" the singer — who welcomed daughter Sienna Princess with husband Russell Wilson on April 28 — captioned a video of party guests singing "Happy Birthday" to her older child.

EMERSON SWISHER

Nick and JoAnna Garcia Swisher's older daughter Emerson Jay hits 4 years old on May 21 — and her mama is sharing her pride on Instagram.

"Emme Jay, 4 years ago today you changed our world forever," Garcia Swisher captioned an adorable photo set. "Our hearts are so full with pride as we watch you grow into the sweetest, wildest, hilarious, and most fun princess rockstar ever."

She adds, "Your daddy and I love you more than you will ever know and we can't wait to see what year FOUR brings your way. ❤️❤️❤️❤️"

MCCOY PORTER

McCoy Lee is officially past the baby stage as of May 23, when his dad Scott Porter shared an adorable photo of the toddler in a swing.

"Happy Birthday to my little man," wrote the actor, who is currently expecting his second child with wife Kelsey.

"What they say is true, it goes sooooo fast. We love you, #BigBoyMcCoy!!!"

SHILOH JOLIE-PITT

Angelina Jolie and Brad Pitt's daughter Shiloh Nouvel is somehow already turning 11 years old on May 27. It seems like just yesterday she was hanging out with her dad on the set of The Curious Case of Benjamin Button.

ROYALTY BROWN

The only child of Chris Brown, daughter Royalty, turns 3 years old on May 27.

"MY BEAUTIFUL BABY GIRL IS OFFICIALLY 3 YEAR OLD!!!!❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️," Brown captioned a pro snap of his adorable daughter. "HBD RO RO! I LOVE YOU."

CADENCE BRIDGES

Ludacris' youngest daughter Cadence Gaëlle turns 2 on May 28, and this year celebrated with a huge helping of love from her daddy.

"To My Youngest and Most Rambunctious! We named you Cadence because the flow, rhythm of events, and patterns in which you make us experience life with you are unmatched and unprecedented!" the rapper captioned an Instagram snap of himself and his little girl.

"I love you with all I have to GIVE and I Thank GOD for you. Here's to the Wonderful 2's! HAPPY BIRTHDAY 🎁🙏🏾 #daddyslittlegirl," he added.

KENZO HOUNSOU

Kimora Lee Simmons' older son Kenzo Lee turns 8 on May 30, and the proud mom of four used Instagram to share a photo from his party — including a huge three-tier cake that looked almost as tall as the birthday boy.

"Happy Birthday Young Sir!! We love you so much! You make us all super proud! Have a great day a week early!" Simmons captioned the memorable moment.

JUSTICE "JJ" ACKLES

Jensen Ackles became a dad to twins in December. But before they came along, their big sister Justice Jay, a.ka. "JJ," made parents of the actor and his wife Danneel Harris Ackles.

"4 years ago, today, she came in to this world," Ackles captioned a May 30 snap of his older daughter. "And changed my life forever. #happybirthday JJ."

EVERLY TATUM

Everly just squeezes a May birthday in on the 31st, turning 4 as she celebrates with parents Channing and Jenna Dewan Tatum.

"Celebrating this little angel turning 4 today....!!!!!!" her mama wrote next to an Instagram photo on Everly's big day.

"I love you so much little monkey Evie 💕💕💕💕💕💕"

PRESLEY RATHBONE

Presley Bowie — the baby girl of Jackson Rathbone and wife Sheila Hafsadi — celebrated turning 1 on May 31 in a variety of dresses and an adorable flower crown, alongside her parents and big brother Monroe Jackson VI, 4½.

"Love being a dad to a beautiful little girl. Terrified of the teenage years... Stay a baby forever!" Rathbone captioned a series of Instagram snaps from Presley's party.