Are you ready to make a splash at your child’s next birthday party?
Well, Major League Mommy has definitely got you covered with these exciting Little Mermaid Birthday Party ideas.
From DIY decorations to under-the-sea-themed snacks and games, we will provide all the inspiration you need to create an absolutely phenomenal celebration for your little mermaid and her friends.
Follow along as we dive into the party-planning process and explore the wonderful undersea world of a Little Mermaid birthday party.

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Create a seaworthy invitation
You know, every good party starts with an invitation. And this party is no exception.
To truly transport your guests to an undersea wonderland, start with an attention-grabbing invitation that sets the tone for the entire party.
A fun and creative option is to send out message-in-a-bottle invitations. All you need are small glass bottles, some sand, and your invitations rolled up like scrolls. Tie them with twine or ribbons and include some sea-themed confetti or small sea creature toys.
Alternatively, you could design your own invitations with sea creature graphics or use a mermaid tail-shaped template.
Whatever you choose, make sure to include all the important details like the date, time, location, RSVP information, and any specific instructions for costume or dress code.
Using these ideas for your invitations, your guests will definitely be eager to dive in and join the fun!
Set the scene with Under the Sea-themed decorations
Transform your party space into an enchanting underwater oasis by decking it out with the best ocean-themed decor.
From glittering blue and green streamers to hanging jellyfish lanterns, there are countless ways to bring the magic of the sea to life.
Cluster starfish and seashells on tables and around the room, and scatter blue and green confetti on the tabletops to simulate ocean waves.
Need some more ideas?
Fill clear glass jars with sand, shells, and miniature starfish to create charming centerpieces.
Don’t forget to set up a backdrop for your DIY photo booth, which we’ll talk more about in the next section.
With the right decorations, your little mermaid and her friends will feel like they’ve actually been transported to an underwater wonderland.
To help you out with your planning, we’ve included some of the best Little Mermaid Party Decorations on Amazon below.

Little Mermaid Birthday Party Decorations Kit
272 pieces

Mermaid Balloon Garland
108 Balloons in kit

Blue Hanging Paper Jelly Fish Lanterns
6 lanterns- 2 light blue, 2 blue, 2 dark blue

Bubble Garlands
4 strings of 7 feet 2D garlands

Fish Net Wall Decoration
Made from quality cotton and shells
DIY a whimsical photo booth
A party isn’t complete without a photo booth to capture all the fun moments.
Creating an underwater-themed photo booth can be the perfect addition to your little mermaid’s under the sea party.
Start by setting up a backdrop with ocean-themed decorations like a vibrant coral reef or shimmering seaweed.
You can easily make your own backdrop with streamers, balloons, and paper cutouts. Add some props like seashell glasses, mermaid crowns, and starfish wands to bring extra magic to the photos.
Don’t forget to set up a camera or phone on a tripod to take pictures or videos.
You can even print out instant photos for your guests to take home as a party favor.
With a DIY photo booth, your little mermaid and her friends will have a blast creating memories that will last a lifetime.
Want more DIY Mermaid Birthday Party Decorations? You can check out our Mermaid Party Pinterest board for even more DIY ideas!
Make a splash with under the sea snacks
Now that the decorations and activities are sorted, it’s time to talk about the food.
When it comes to snacks, you have endless possibilities to get creative with this particular theme!
One idea to consider is jelly-filled cupcakes. And by adding a few drops of blue food coloring to the mix and topping them off with blue icing and a small candy fish, you can create a delicious and festive treat that fits right into your theme.
Another option is to serve up some oceanic fruit skewers for a healthier option.
Cut up your little one’s favorite fruits into small, bite-sized pieces and skewer them onto wooden sticks. You can also add marshmallow clouds for added sweetness and a whimsical touch. You can also serve up veggies with dip in a hollowed-out bell pepper that resembles a coral reef.
Savory snacks like goldfish crackers or popcorn can also be served in decorative beach pails or shells.
By incorporating under-the-sea-themed snacks into your party spread, you will make a big splash amongst your little mermaid and her guests.
But wait… there’s more!
You know we can’t talk about party food without discussing the cake!
Make a Big Splash with a Mermaid Birthday Cake
No birthday party is complete without a cake, and a little mermaid birthday theme is the perfect opportunity to get creative with cake decorations.
A sea-inspired cake can feature elements like fondant seaweed, graham cracker sand, and edible seashells.
The color palette can include shades of blue, green, and coral, mirroring the hues of the ocean floor.
An ocean-inspired cake isn’t just visually stunning; it’s also a delicious way to tie the theme of your party together.
Serve it up alongside your other under-the-sea snacks for a full spread that your guests will love.
Pro Tip: The cake can also double as a fantastic centerpiece for your party spread, making it an easy way to bring the theme to life.
Make sure to take plenty of photos of the cake before it’s devoured by the little mermaids and mermen in attendance. And once the cake has been sliced and enjoyed, it’s time to move onto the next part of the party: themed party games.,
Activities
Play themed party games
Alright, now let’s talk about some fun games and activities to include in your party.
A scavenger hunt for hidden treasures can be a thrilling adventure for your little mermaid and her party guests.
Create clues that lead to hidden treasure chests filled with goodies like seashell jewelry, bubbles, or even small plush sea creatures. Encourage teamwork and collaboration among the participants to make it more fun.
Another fun game idea is a “pin the tail on the mermaid” activity. Hang a poster of a mermaid on the wall and have each guest take turns trying to pin the tail in the correct spot while blindfolded.
For extra fun, add some under the sea sound effects or music to really set the mood.
If you’re looking for a more active game, consider a game of “shark and minnows.“
One guest is the designated “shark” and the rest are “minnows.” The minnows must try to cross a designated area without being tagged by the shark. Whoever is tagged becomes the shark for the next round.

Have a mermaid makeover station
If you want to do something a little more relaxing, this makeover station is a fantastic idea! Set up a mermaid makeover station for your guests to get in touch with their inner sea creatures.
Provide glittery makeup, mermaid-inspired nail polish, and temporary tattoos for everyone to enjoy.
Don’t forget to have a mirror nearby so they can admire their new looks. Once everyone is dolled up, they’ll be ready for the next activity – a treasure hunt!
Incorporate fun water activities
To add more fun and excitement to your little mermaid’s under the sea party, incorporate some water activities.
You can make sure the kids come ready in their swimsuits and have them participate in various water games.
If you have access to a pool, plan games like water polo, pool volleyball, or Marco Polo.
If you don’t have a pool, you can set up a sprinkler or a small water slide to get the kids splashing around.
Additionally, you can put out a table with water guns or water balloons for some water warfare.
Craft some fun party favors
After all the underwater adventures and games, your little mermaid and her friends will surely be in high spirits.
To keep the festive mood going, why not give them some fun party favors to take home? Here are a few ideas to get you started.
Seashell Necklaces
Collect some seashells (you can find them in craft stores or online) and string them together to make a cute necklace.
You can also add some colored beads to give it some extra flair. This way, the kids can have a piece of the party with them even after it’s over.
DIY Mermaid Tail
If you’re feeling crafty, you can create mermaid tails out of felt or fabric. Cut the fabric into fish-scale shapes and glue them onto a piece of fabric that fits around the child’s waist. You can even add some glitter for some extra sparkle. The kids will love pretending to swim like mermaids at home.
Mermaid Hair Ties
Take some plain hair ties and glue on some sea-themed charms like starfish, seashells, or even small mermaid tails. This will not only keep their hair out of their faces during the party but also serve as a reminder of the fun they had.
Concluding Your Little Mermaid Birthday Party
You know we always recommend sending your guests with a little treat after the party. And it’s a great idea to connect your party favors with your under-the-sea theme.
Everyone loves bubbles, and you can create some underwater-themed ones with a simple recipe. Mix together water, dish soap, and blue food coloring to create a bubbly ocean effect. You can put them in small containers with lids that have cute labels and hand them out as party favors.
You could also let any of the aforementioned crafts double as their parting gift.
Whatever you choose, I’m sure your guests will appreciate the thought.
Ultimately, incorporating these 10 magical under the sea party ideas will certainly help you create an unforgettable celebration for your little mermaid’s special day.
From seaworthy invitations to sea-inspired cakes, mermaid makeovers, and treasure hunts, your child and their friends will have a blast.
Whether you choose to DIY or opt for pre-made decorations, snacks, and games, I hope this post has made your planning a lot easier!
Your child’s birthday party should be one to remember, and with these little mermaid birthday party ideas, it definitely will be. So grab your glitter and seashells, and get ready for a party that will surely be a hit with all the kiddos!