10 Adorable Pool Party Decorations for Kids Birthday That Will Make a Splash
As an event planner and blogger who’s seen countless birthday themes come to life, one thing I always notice? Nothing gets kids more excited than a splash-filled pool party, especially when it’s bursting with cute, colorful decorations! Whether you're planning a tropical paradise, a magical mermaid lagoon, or a shark zone for your little adventurer, having the right décor sets the tone and brings the whole vibe together.
In writing this post, I couldn’t help but think of a pool party I helped plan last summer for a client’s twin kids—a boy and a girl. We combined both mermaid and pirate themes, and let me tell you—it was a Pinterest dream come true. The key to success? Whimsical, thoughtful, and totally Instagram-worthy pool party decorations for kids birthday fun!
So today, I’m sharing 10 adorable and doable decoration ideas perfect for a summer splash. These are ideal for both boys and girls, with themes ranging from beachy to tropical, simple to DIY-friendly. Ready to dive in?
This post may contain affiliate links at no extra cost to you. Please read our full disclosure here to find out more.
1. Tropical-Themed Welcome Sign & Entryway Decor
First impressions matter! Greet your little guests with a pop of tropical color by setting up a welcome station that screams “paradise.”
Think a chalkboard sign that says “Aloha! Let’s Make a Splash!” framed by palm leaves and hibiscus flowers. You can even use a DIY balloon garland with bright colors like coral, teal, and sunshine yellow to create an archway.
This idea sets the tone for a summer celebration and builds instant excitement as kids walk in. Bonus: it's perfect for snapping those first few photos!
2. Mermaid Magic Underwater Decor (Perfect for Girls)
If you're planning a party for a little girl who’s obsessed with mermaids, this theme never fails. Turn your poolside into an underwater wonderland with glimmering pastels, pearl balloon garlands, and hanging jellyfish made from paper lanterns and streamers.
One trick I’ve used is laying iridescent table runners across your table decor, mimicking the shimmer of a mermaid tail. Add in starfish cutouts, shells, and nets for an authentic under-the-sea vibe.
For a super cute touch, fill a clear vase with blue water beads and insert LED lights—it looks like a glowing ocean treasure!
3. Shark & Pirate Splash Zone (Perfect for Boys)
Now, for the adventurous types! If your birthday boy is into pirates, sharks, or anything bold and exciting, create a mini “Splash Zone” with themed inflatables and signage like “Beware: Sharks Ahead!”
Scatter inflatable floats like pirate ships or giant sharks across the pool. Hang black and red banners and offer kids pirate hats or eyepatches at the entrance. Add plastic treasure coins in the water for treasure-hunting fun!
When I designed a shark-themed party, we even added DIY shark fin cutouts to the fence. The boys were thrilled to have their own "territory" to rule.
4. DIY Pool Float Centerpieces for Tables
Let’s talk table decor—because every snack and cake station deserves to be fabulous! One of my favorite hacks is using mini inflatable floats as centerpieces. You can find tiny flamingos or donuts and place cups, snacks, or drinks inside them.
It’s a clever way to stay on theme and avoid clutter. You can even anchor balloons to them for extra flair!
5. Summer-Inspired Balloon Garlands & Water Droplets
If you're on a budget but still want to make a splash, balloons are your BFF. Choose blue, aqua, and white shades to mimic water, and add paper water droplets hanging from the ceiling or pergola.
You don’t need to be a balloon artist—many kits come with everything you need, including glue dots and a pump. And they instantly brighten up the party without needing much else!
Here’s a favorite I’ve used multiple times:
Amazon Product Recommendation #1
Product: Balloon Garland Kit – Blue & Aqua Water Theme
Why I Love It: This kit includes 120 balloons in various shades of blue and teal—perfect for a water-themed party. It also includes everything needed to create a show-stopping balloon arch without the stress.
Create a stunning splash effect with this easy-to-use balloon garland kit—your guests (and photos!) will thank you.
6. Photo Booth Fun with Beach Props
Kids love a good photo booth, and so do moms who want adorable memories! Set up a backdrop with tropical leaves, balloons, and beachy props like oversized sunglasses, surfboards, and fruity drinks (mocktails, of course).
Use an inflatable palm tree or surfboard as a prop station and let the kids get silly.
One party I planned even included a mini kiddie pool filled with beach balls—perfect for younger guests to “pose” in while sitting. The photos were priceless!
Amazon Product Recommendation #2
Product: Inflatable Photo Booth Prop Kit – Beach & Pool Party Edition
Why I Love It: This kit includes over 20 props like snorkels, sunglasses, flamingos, and beach hats. It makes setting up a kid-friendly photo station a breeze.
Let your little guests strike a pose with this adorable beach-themed prop set—perfect for Insta-worthy moments!
7. Poolside Snack & Cake Table Styling
Food deserves its moment too! Use colorful trays, tiered stands, and theme-coordinated napkins and cups. For mermaid or beach themes, use brown sugar to mimic sand under cupcakes or cookies.
Fruit kabobs are a hit, and so are goldfish crackers in mini beach buckets. Don’t forget a cute cake topper or water-themed cookies in the shape of flip-flops or seashells!
A super helpful tool I never party without:
Amazon Product Recommendation #3
Product: 3-Tier Cupcake and Snack Display Stand – Ocean Blue
Why I Love It: Lightweight but sturdy, this stand displays cupcakes, cookies, or fruit in a neat, eye-catching way. The ocean-blue color fits any pool party theme.
Upgrade your snack table with this elegant and reusable 3-tier display stand—it’s a party must-have for stylish moms!
8. Inflatable Pool Toys & Water Games Decor
Why not let the decor double as entertainment? Toss oversized flamingo or unicorn floats into the pool. Kids LOVE them, and they add personality to the space.
For a school party or a larger crowd, add a splash pad area or mini water slide. You can also DIY a sponge toss game using cut-up colorful sponges!
One party I did included a flamingo ring toss game using pool noodles—fun and budget-friendly!
9. Beach Bucket Party Favors Display
Give your favors a functional twist by placing them in mini beach buckets with each child’s name. Fill them with sunglasses, tropical stickers, mini squirt toys, or candy.
Set them up as part of your décor—it looks organized and festive. I usually line them along a table with a “Thanks for Making a Splash!” sign.
It’s a sweet way to end the party and lets guests take home part of the fun.
10. Simple DIY Hanging Decor & Streamers
Not everything has to be store-bought. Kids love color and movement, so use crepe paper streamers, paper fans, and DIY sun and cloud cutouts. Hang them around umbrellas, fences, or patios.
For extra sparkle, string LED fairy lights around your main table or snack station. It adds whimsy—especially if the party runs into early evening.
This is also where your kids can help! I once had a mom involve her kids in making tissue paper fish. It kept them entertained pre-party and made them feel part of the magic.
Final Thoughts from a Party Pro
Planning a pool party for kids is all about creating a world where fun, imagination, and water collide. These adorable pool party decorations for kids birthday aren’t just trendy—they’re doable, budget-friendly, and seriously cute.
As a planner and mom, I know the importance of balancing Pinterest-worthy with practical. Every tip I’ve shared here is something I’ve used personally or with clients—and I’ve seen firsthand how decorations create that wow moment that makes kids feel special.
Whether you're throwing a mermaid bash for your daughter, a shark attack party for your son, or a tropical beach celebration for both, these ideas will help you make it unforgettable.
Now, over to you! Which idea are you excited to try first? Drop your thoughts in the comments or tag me in your party pics—I’d love to see your splash-tastic celebrations!