25 Cutest “Oneder the Sea” (Under the Sea Birthday Party) Ideas
An under the sea birthday party will be a magical and joyful way to celebrate a baby’s first year. This theme offers endless creative expressions for an under the sea first birthday party, an under the sea mermaid birthday party, and many celebrations.
For parents looking to create an unforgettable first birthday party, CustomAny‘s guide features 25 of the cutest ideas to make the celebration feel like an underwater adventure. Get ready to get creative with these adorable and easy-to-plan ideas!
Decoration Ideas for an Under the Sea Birthday Party
The first step in hosting a perfect under the sea birthday party is decorating. Here are some creative Oneder the sea birthday party decorations to transform any space into an enchanting underwater world:
1. Ocean-Themed Backdrop
A stunning backdrop is the perfect way to set the mood for any party. Therefore, you can create a DIY underwater scene using blue and green streamers to mimic the flowing movement of water.
Then, hang clear bubble balloons to represent air bubbles rising to the surface, adding depth and dimension to your backdrop.
2. Underwater Balloon Arch
A balloon arch in shades of blue, teal, and purple instantly makes you think of the ocean. You can also enhance the look by attaching seashells and fish cutouts to the arch. This vibrant entrance is a wonderful way to welcome guests into your under the sea birthday party.
3. “Oneder the Sea” Welcome Sign
Besides the balloon arch, personalized “Oneder the Sea” welcome signs will make the entrance of your Oneder the sea birthday party even more special.
A wooden board customized with our waterproof transfer stickers is a great choice, especially if the party is held near water or a pool. You can choose stickers that feature:
- Bubbles
- Coral
- Smiling octopus
- Phrase “Welcome to [Baby’s Name]’s Oneder the Sea Adventure!”
- …
4. Mermaid & Sea Creature Cutouts
To make the space more interesting, let’s bring the ocean to your under the sea birthday party with cardboard cutouts of:
- Mermaids
- Turtles
- Seahorses
- Fish
It’s also a great idea to encourage creativity by letting kids color the cutouts themselves. Then, you can place these under the sea themed birthday party decorations around the venue.
5. DIY Jellyfish Lanterns
Another enchanting decoration idea is DIY jellyfish lanterns. Paper lanterns with long, flowing streamers can be hung from the ceiling to make it look like jellyfish floating through the water. Choosing iridescent or pastel streamers will make them shine beautifully under the lights.
Cute & Themed Food Ideas
Providing your guests with delicious food is also a great way to leave a lasting impression. So, let’s discover some cute and delicious under the sea birthday party food ideas for both kids and adults.
6. “Sea Water” Punch
Blue lemonade or Gatorade served in a clear drink dispenser.
A refreshing “Sea Water” punch is a fun and simple drink option. Blue lemonade or blue Gatorade served in a clear drink dispenser will resemble the ocean and help guests stay refreshed.
7. “Clam” Cookies
For a sweet treat, “Clam” cookies will be a delightful addition. Vanilla wafers sandwiched with white frosting and a small candy pearl inside will create an adorable seashell look.
8. Starfish Sandwiches
Starfish sandwiches are also great under the sea birthday party ideas for food. Classic PB&J or ham and cheese sandwiches cut into star shapes will be both cute and easy to eat.
9. Octopus Hot Dogs
How about creating a fun and quirky dish with octopus hot dogs? By slicing the bottom half of a hot dog into strips and placing it on a bed of mac and cheese, it will look like a tiny octopus sitting on a sea of cheesy waves.
10. Fish Bowl Jello
Fish bowl Jello will be a fun, ocean-themed dessert. You can make individual blue Jello cups with gummy fish inside to resemble mini fish bowls.
11. Seashell Pasta Salad
Seashell pasta salad will add a great option to the table at your under the sea birthday party. To make it, you can use pasta shells as the base. Next, add colorful veggies and cheese to make it both tasty and appealing.
12. “Ocean Waves” Cake or Cupcakes
An “Ocean Waves” cake or cupcakes is the perfect treat to complete the theme. You can:
- Decorate them with blue ombré frosting to resemble ocean waves
- Top them with edible seashells or a fondant mermaid
- Make a cake shaped like the number 1, adorn it with ocean-themed decorations.
Fun Party Activities
Now, it’s time to make your under the sea theme birthday party memorable and enjoyable with interesting activities. Below, we’ve listed some exciting under the sea birthday party games and activities for one year old birthday kids and guests (both toddlers and older kids).
13. “Catch the Fish” Game
A kiddie pool filled with small plastic fish will create a fun fishing adventure for little ones. With small nets in hand, they can catch the floating fish, improving their coordination while enjoying a simple yet exciting water activity.
14. Mermaid or Pirate Dress-Up Corner
A dress-up station with mermaid tails, pirate hats, and seashell crowns allows kids to transform into ocean characters. This activity is great for sparking imagination and creating adorable photos.
15. Bubble Party!
A bubble machine will transform the party space into an enchanting underwater world. Kids will certainly love running around, popping bubbles, and watching them float through the air.
16. Sand Sensory Play Table
Prepare a shallow bin and you can turn it into a creative play area for toddlers by filling it with:
- Kinetic sand
- Seashells
- Mini shovels
They can dig, scoop, and explore different textures while staying engaged in creative play.
17. “Feed the Shark” Toss Game
If you are looking for a game for older kids, this game is perfect. A large shark cutout with an open mouth will make for a fun and interactive bean bag toss game. It challenges them by aiming and tossing bean bags into the shark’s mouth.
Party Favors & Goodie Bags
Sending guests home with these themed under the sea birthday party favors to thank them for celebrating this special occasion:
18. Mini Plush Sea Creatures
Small stuffed turtles, fish, or sharks make adorable keepsakes for little guests to take home.
19. DIY Message in a Bottle
Creating tiny glass or plastic bottles filled with a personalized note or a small scroll is a meaningful way to make a keepsake for your under the sea birthday party. You can make them more special by including glitter or tiny seashells inside.
20. Seashell Necklaces
Ocean-inspired jewelry, like pre-made or DIY seashell necklaces, will make for a fun and wearable gift. You can use small seashells and colorful beads to craft these accessories, which kids can wear or keep as a keepsake.
21. Ocean-Themed Coloring Books
A set of cute “Under the Sea” coloring pages paired with crayons provides a creative activity for kids to enjoy at home. You can pick for themed designs like:
- Whales
- Mermaid
- Starfish
22. “Mermaid Bubbles” or “Pirate Treasure” Bags
For “Mermaid Bubbles,” it’s ideal to include tiny bubble wands labeled “Mermaid Bubbles.” Alternatively, “Pirate Treasure” bags can be filled with gold chocolate coins or small trinkets, giving little ones the feeling of “Pirate Treasure.”
Both options are simple, fun, and perfectly suitable for any oneder the sea birthday party girl or oneder the sea birthday party boy.
23. Starfish Wands
DIY wooden starfish wands will make a magical favor for little guests. They are easily made by crafting wooden wands with starfish-shaped toppers, decorated with ribbons and glitter.
24. Fish-Shaped Sunglasses
These adorable sunglasses, designed in the shape of fish or decorated with ocean-inspired patterns, are ideal for toddlers. Not only do they protect little eyes from the sun, but they also add a playful touch to the party.
25. Custom “Oneder the Sea” Die-cut Stickers
Custom die-cut stickers featuring the “Oneder the Sea” theme are a versatile and personalized party favor that guests will adore. These stickers can include:
- The baby’s name
- Cute sea creatures like fish, starfish, or mermaids
- Playful underwater designs
Kids can use them to decorate their personal items, such as eating utensils, milk bottles, pencil boxes, or lunch boxes to add more creativity to their everyday belongings.
Last words
An under the sea birthday party will create a fun and memorable celebration filled with ocean-inspired decorations, delicious treats, exciting activities, and thoughtful favors. Additionally, personalized stickers will make the event even more special for your little guests.
Besides die-cut and waterproof transfer stickers, you can also consider exploring other sticker options such as clear stickers or holographic stickers for creativity. These unique choices can bring even more excitement and charm to your under the sea birthday party, making it an unforgettable experience!
