Make a splash with these mermaid-themed kids’ birthday party ideas

A party scene shows a table top and wall decorated with mermaid and under-the-sea themed party supplies including banners, honeycomb decor, balloons, and cake toppers.
Paperless Post BlogParty Décor > Make a splash with these mermaid-themed kids’ birthday party ideas

Party planners—your attention, please. We’re about to dive into a party theme that inspires as much delight as the birthday kid, themself: the mermaid birthday party.

A mermaid-themed party is an opportunity to celebrate another year with under-the-sea sparkle and glee. But before you can grant your child’s birthday wish for shimmering scales and mermaid tails, you’ll need all the mermaid birthday party ideas you can get your fins on. 

Feeling like a fish out of water? Don’t worry—we have all the mermaid-themed birthday ideas you need. Read on.


A young girl in a claw-foot bath tub decorated with mermaid party supplies. Right: A birthday invitation with mermaids and sea creatures in the ocean.Mermaid Fringe Garland by Meri Meri; “Vintage Mermaid” by Rifle Paper Co. for Paperless Post.

Scale up the scene with mermaid decor

Your little mermaid may dream of zipping through an underwater paradise with all their aquatic friends, but how does that translate to an equally marvelous party? To start with, we’re going to need to define your own unique mermaid theme. 

Choosing a mermaid color scheme will help you narrow down your mermaid party decor. Some classic mermaid hues include:


— Sea-foam green


— Pale pink


— Turquoise blue


— All shades of purple


— Shell white


– Iridescent pearl


Don’t be afraid to change it up, or even create your own brand new mermaid party theme. Perhaps, for example, your mermaid likes to imagine they live in a dolphin-filled poolside paradise, or that they rule the great blue seas as a mermaid princess. Use these thematic elements to craft an overarching mermaid party theme and then accessorize accordingly.

Whatever colors and theme you choose, you can make your birthday mermaid feel at home with some underwater motifs for your decorations. Set the mermaid party scene with:


— Shells and sea creatures


— Seaweed and coral


— Sparkling and shimmering scales


— Iridescent balloons, ribbons, and streamers


Want to mimic the underwater atmosphere? Hang a backdrop with drapes of turquoise tulle or pale blue fabric. To create a truly aquatic setting, however, you’ll also need some mermaid party supplies and decorations—and luckily, our Party Shop is filled with them. 

Mermaid party supplies from Paperless Post Party Shop

Shimmer and shine with mermaid-themed party supplies 

Set the scene of your under-the-sea extravaganza with some fantastic supplies that will top off your mermaid birthday party concept. To make the underwater atmosphere feel as dazzling as the ocean, leave no corner of the mermaid-themed party room untouched.


— Make your mermaid cake a showstopper: Is any birthday party complete without an awe-inspiring cake? Present it on a coral-colored Cake Stand and make this dessert the centerpiece with some adorable Mermaid Cake Toppers (1). You could even have mermaid cupcakes to compliment your coral cake. Don’t forget to have the birthday mermaid make a wish on some Glitter Candles.


— Set the table: Serve up your mermaid cake on mermaid plates with mermaid napkins (3), and be sure to have some Mermaid Scalloped Fringe Cups (2) on hand to quench any little mermaids’ thirst. 


— Bedazzle the party guests: Celebrate the birthday child’s shining moment with a Gold Sparkle Cape (the sequins look like scales!) and allow guests to embellish their own pretty little heads with glittering Mermaid Party Crowns (4) that can also double as mermaid party favors.


— Garnish the gathering room: To give your party space some underwater glamor, create a photo wall with a Blue Balloons & Streamers Kit (5). Add more mer-magic with a playful Mermaid Fringe Garland.


— Keep the joy going: Want to send guests home with some magical mermaid memories? Fill up some Mermaid Party Bags (6) with sea-themed party favors, like  a set of Mermaid Tattoos or mini Mermaid Pinatas.


An invitation with a child mermaid surrounded by goldfish. Right: Party decor with a blue balloon installation made to resemble a mermaid tail.Curious Mermaid” by Vashti Harrison for Paperless Post; Image by Kelsey Farrell.

Choose a magical mermaid location 

Still a little stuck on the perfect mermaid party theme? Deciding where your kids’ party will take place can be a fantastic way to find inspiration for the rest of your planning. Here are some ideas to give all your beautiful mermaid decor the perfect setting:


— Poolside paradise: A swimming pool, either at your home or in your neighborhood, is the perfect place to host an aquatic-themed mermaid party that really makes a splash. Use your party supplies to decorate the pool deck (and some beach chairs and tables) and trade the costumes for swimwear. You can even add some cute sea creature and shell-themed floats. Of course, make sure there are enough adults around to supervise pool time. 


— Enchanted mermaid island: Is your party location landlocked? No sweat—your backyard can make a great setting for an island-themed birthday party. To give the celebration a beachy touch, let young mermaids enjoy some sandcastle playtime with a baby pool or sandbox full of sand in the backyard. You can hide some buried treasure inside for all to discover. 


— Mermaid princess castle: If you’re wondering how to pull off a princess party when you’re stuck indoors, no worries—it’s the perfect occasion to transform your home into a deep-sea castle for your mermaid princess. Add to the atmosphere with a sea-themed soundtrack and a bubble machine to add some extra undersea delight.


— Underwater dreamland – Are you lucky enough to live near an aquarium? Try renting out a party room on site and let your guests explore the enchanting aquatic scenery as they make fish friends. Don’t forget to let them dress up in their mermaid wear first, of course.


A birthday cake and cupcakes with mermaid cake toppers. Right: An invitation with several mermaids and some ocean plants and shells.Cake Toppers by Meri Meri; “Mermaids In Waiting” by Meri Meri for Paperless Post.

Snack on sweet mermaid treats

Are your mermaids feeling famished after all that swimming? Any successful mermaid party should come equipped with some tasty mermaid treats. If you and the birthday child aren’t fans of seafood, however, don’t fret. There are plenty of mermaid-inspired sweet treats to please the palate.


— Cookie shells: Use a shell-shaped cookie cutter to bake your favorite sugar cookies. Top with pastel frosting and all the shimmering sprinkles you can find.


— Mermaid tails: We love these edible mermaid tails made from chocolate-covered pretzels. All you need are some pretzel rods, chocolate candy melts, and sprinkles galore. 


— Under-the-sea snacks: Make your own mermaid Jell-O cups with blue raspberry Jell-O. Before it sets, drop in some sea creature-shaped gummies for extra mer-points.


— Mermaid parfait: For an ombre mermaid treat, mix three separate bowls of vanilla yogurt each with a different shade of food coloring: blue, purple, and green, or pink, yellow, and orange, for example. Layer each color in clear plastic cups to create a gradient treat. Top with your favorite fruit and berries (and plenty of sparkly sprinkles, of course).


A pink invitation with a mermaid and a large oyster shell with a pearl inside. Right: A child wearing a gold mermaid tail and crown blows bubbles.Mermaid Cove” by Paperless Post; Mermaid Tail DIY by Meri Meri.

Plan some mermaid-inspired playtime

Whether your mermaids will be celebrating poolside or on land, mermaid party games are a perfect way to keep the fun flowing. While you can put a seaside spin on practically any party game, we have a few up our sequined sleeves just for you:


— Make a mermaid dress-up station: Before the games begin, give party guests a chance to step into their true mermaid persona with mermaid costume supplies. Set up a mermaid dress-up station with a mirror and baskets of mermaid adornments, such as sequined skirts, shell necklaces, and tiaras.


— Play sharks and mermaids: A take on the classic sharks and minnows game, this is a perfect game to inspire some mermaid frolicking and fun. Start by designating a “shark” (and provide them with a fin-shaped party hat for extra fun). Mermaids line up on one side of the yard, and the shark stands in the middle. Mermaids then race back and forth, trying not to get tagged by the shark. Those who do get tagged become sharks themselves, but the last mermaid swimming is crowned the winner. (A mermaid tip—this game is equally fun in the pool!) 


— Mermaid tail race: We adore this idea of turning a regular sack race into a mermaid tail race. You’ll need to acquire some potato sacks or pillowcases, but you can then dye them blue and green or decorate them with glitter glue and stick-on gems. Alternatively, let mermaids decorate their own tails with fabric markers and stickers. Once they’re all beautified, have mermaids participate in a sack race by hopping across the yard in their mermaid tails.

Wording for an aquatic invitation

Planning your mermaid party at an enchanting blue lagoon, inside a mesmerizing aquarium, or in your landlocked backyard? Either way, start by picking out some magical mermaid party invitations to request the presence of all the birthday child’s mer-friends.


Here are some examples:

Gabby is turning five…

And we’re celebrating under the sea!

Join us for a mermaid-themed birthday bash

Saturday, April 2nd

4 o’ clock in the afternoon


Please RSVP 

Or, for a mermaid pool party:

Our little mermaid is turning six!

Join us for Ava’s poolside celebration

Saturday, June 9th 

2 p.m.

At the Anderson lagoon


Feel free to bring your swimsuits and pool party gear (floats, goggles, etc)


Planning a dual party to please both the pirates and fish-tailed friends? Your wording can help here, too:

Ahoy, mermaids!

It’s Andrew and Becca’s birthday

Join us for a double birthday celebration

Friday, April 15

At 3 p.m.

The Jones Aquarium

Come dressed in your favorite mermaid or pirate costume!


Once your invitees receive their thoughtfully worded and imaginative invitations, their excitement will have them wanting to swim all the way to the party site without pause.

A Flyer invite shows a shimmering scallop pinata and a mermaid tail.Shell Piñata” Flyer by Paperless Post.

For mesmerizing mermaid invitations and supplies, choose Paperless Post

When you celebrate your little mermaid’s birthday, it’s about more than just another year gone by. It’s about creating joyful memories for years to come—and lifting up all the quirks, traits, and interests that make your kid so one-of-a-kind.

Now that you’re well-equipped to plan a mermaid birthday party that’s as unique as they are, it’s time to discover the perfect online mermaid birthday party invitations at Paperless Post

And there’s no need to search for party decor like you’re diving for buried pirate treasure: We’ve got all the shimmering mermaid supplies to match your invitations and make your party go extra swimmingly, right at the Party Shop



Browse Mermaid Themed Invitations


Editor’s note: Party Shop shipping is only available in the continental US.