You don’t need to buy an entire matching party range to create an incredible mermaid birthday. This real party is packed with DIY mermaid decoration ideas, from homemade jellyfish and balloon garlands to op-shop treasures and repurposed props.
Some of the best children’s parties aren’t created by buying everything in one matching range.
They’re pulled together with a little imagination, a few clever finds and plenty of DIY.
That’s exactly what mum Monica did for this gorgeous mermaid birthday party.
She mixed balloon garlands and shimmering backdrops with homemade jellyfish, painted decorations, Marketplace finds and treasures picked up from op shops to completely transform the party space.
The result is full of ideas you can recreate at home, whether you’re planning a huge mermaid celebration or simply looking for a few DIY decorations to make your party feel special.
For everything else you need to plan the celebration, head to our complete Mermaid Party Ideas guide.
Start With a Mermaid Colour Palette
For an under-the-sea mermaid party, try combinations such as:
- Aqua, lavender and pink
- Blue, teal and purple
- Pastels and iridescent silver
- Aqua, coral and gold
- Blue, green and pearl white
Once you’ve chosen your palette, repeat those colours throughout the balloons, backdrop, table decorations and cake.
This makes even decorations collected from completely different shops feel as though they belong together.
DIY Mermaid Balloon Garland
Balloon garlands can completely transform a party space and you don’t necessarily need to pay someone to install one.
For this real mermaid party, Monica created the balloon garlands herself using kits purchased from Kmart.
If you’re making your own, a kit is generally the easiest starting point because it may include balloons in different sizes along with balloon strip and glue dots.
Before buying one, check exactly what’s included.
You’ll usually need:
- Balloons in several sizes
- Balloon decorating strip
- Glue dots
- Balloon pump
- Hooks or removable wall attachments
Mixing balloon sizes helps create the fuller, organic look you often see at professionally styled parties.
You can then add a few separate balloons or small clusters around your dessert table or backdrop to bring everything together.
For current mermaid balloon garlands and other decorations, see our Best Mermaid Party Supplies guide.
Make an Easy Shimmering Mermaid Backdrop
Monica combined a metallic backdrop with fabric found at an op shop to create the backdrop for this party.
This is a brilliant way to make an inexpensive fringe curtain look much more substantial.
Try layering:
- Fabric or a plain tablecloth at the back.
- Metallic fringe curtains over part of the fabric.
- Balloon garlands around the top or side.
- Homemade seaweed or jellyfish decorations.
- Shells or ocean props around the bottom.
You don’t need to cover an entire wall.
Concentrating your decorations around the cake or food table gives you one strong focal point and also creates a natural location for birthday photos.
DIY Hanging Jellyfish Decorations
- Paper bowls
- Paper lanterns
- Honeycomb decorations
- Ribbon
- Curling ribbon
- Streamers
- Crepe paper
Make Your Own Mermaid Seaweed Decorations
Another clever DIY touch was the hanging mermaid decoration Monica created using cupcake liners painted in different shades of green. You can take the same idea and create your own underwater plants and seaweed using inexpensive materials. Try:- Green crepe paper
- Streamers
- Tissue paper
- Painted cupcake liners
- Green ribbon
- Coloured card
Look for Mermaid Props Second-Hand
This is one of my favourite ideas from the entire party.
Instead of buying everything new, Monica found many of the decorations through Marketplace and op shops.
The wave props were Marketplace finds that she repainted, while the treasure chest, fish, shells, crabs and other decorations were sourced second-hand.
Before buying new decorations, look around:
- Facebook Marketplace
- Op shops
- Buy Nothing groups
- Your own cupboards
- Children’s toy boxes
- Friends’ party supplies
- Previous birthday decorations
Treasure chests, shells, baskets, trays, glass jars and fish decorations can all work beautifully for a mermaid theme even if they weren’t originally sold as party supplies.
A coat of paint can also completely change the look of a second-hand prop.
Style Your Mermaid Party Table
The food table is usually one of the most photographed areas at a children’s birthday, so concentrate plenty of your decorating effort here.
Monica used trays and cake stands she already owned, rather than buying an entirely new set for one party.
Before shopping, go through your cupboards and pull out anything that could work.
Look for:
- Cake stands
- Platters
- Serving bowls
- Glass jars
- Wooden boards
- Tiered stands
- Baskets
Using different heights creates a much more interesting display.
Then weave your mermaid theme through the table with shells, pearls, sea creatures, labels and small decorations.
You can see more ideas for filling the table in our Mermaid Party Food guide.
The chest has to be a favourite! This piece, along with the fish, shells, crabs and other decorations just came from Op Shops. Perfect place to look for some bargains.
Most of the trays and stands Monica already has, so it helps to sort through your cupboards before a party.
The mermaid straws, purple table tutu and water labels came from Wish.
DIY Mermaid Craft Station
Decorations can become activities too.
At this party, the children’s table included mermaid crown colouring activities, giving guests somewhere to sit and create between the more energetic parts of the celebration.
You could set up a mermaid craft table with:
- Colour-your-own crowns
- Mermaid colouring pages
- Shell decorating
- Bracelet making
- Mermaid wand decorating
- Design-a-mermaid-tail sheets
- Gem and sticker crafts
Use aqua or purple tablecloths and scatter a few shells or faux pearls around the table to bring it into the overall styling.
Give an Ordinary Piñata a Mermaid Makeover
Another clever DIY idea from this party was the piñata.
Monica bought one from Big W and redecorated it to turn it into a mermaid design, including adding a tail.
This is a useful trick when you can’t find the exact themed product you want.
Start with a piñata in a simple shape and customise it using:
- Tissue paper
- Metallic paper
- Cardboard
- Glitter card
- Ribbon
- Shell shapes
- Mermaid-tail cut-outs
You can use the same approach for plenty of generic party products. Rather than searching endlessly for something officially labelled “mermaid”, look for something in the right colour or basic shape and add your own details.
Don’t Forget the Cake Area
The cake is often part of the decoration itself, so think about where it will sit before you finish styling the table.
Position it against your main backdrop and surround it with a few complementary decorations rather than cluttering the space.
If you’re making your own cake, our DIY Mermaid Pool Cake is packed with step-by-step inspiration.
You can also take a look at our Mermaid Underwater Cake for another DIY option.
How to Create Mermaid Party Decorations on a Budget
The biggest lesson from this real party is that you don’t have to buy every decoration new.
A combination of DIY, second-hand and inexpensive basics can create an amazing result.
Before spending, try this order:
- Decide on your mermaid colour palette.
- Check what party supplies you already own.
- Look through children’s toys and dress-up items.
- Search Marketplace and op shops for larger props.
- Make easy decorations such as seaweed and jellyfish.
- Buy one or two high-impact pieces such as a balloon garland or backdrop.
- Add smaller mermaid details at the end.
Spending your budget on a few high-impact elements rather than dozens of tiny themed products can make the entire party look more impressive.
More Mermaid Party Inspiration
Planning your own mermaid celebration? Explore more ideas:
- Mermaid Party Ideas
- Best Mermaid Party Supplies
- Mermaid Party Food
- DIY Mermaid Pool Cake
- Mermaid Underwater Cake
- Ellie’s 6th Mermaid Birthday Party
- Real Mermaid Birthday Party for a 9-Year-Old
Need more tips when it comes to planning that next important occasion? Check out our DIY party planning checklist and get started today!
