- Age 4-5 - $45.09
- Age 5-6 - $45.09
- Age 6-7 - $45.09
- Age 7-8 - $45.09
- Age 9-10 - $45.09
Kids Mermaid Swimming Costume - Rainbow Tail Swimsuit with Monofin
DELIVERY
- Dispatch: Within 24 Hours
- Registered & Express Post for ALL Orders.
- Pick up is available.
- Easy 14 days returns and exchanges
RETURNS
If you do not like the product you can return it within 14 days - no questions asked. This excludes stockings, gloves, swimwear and clearance sale items. We have an easy and hassle-free return policy. Please look at our Delivery & Returns section for further information.
PRODUCT DETAILS
What's in the Box
- Hot pink halter bikini top with double-tier ruffle detail
- Rainbow gradient mermaid tail pants with side zipper (pink/purple/cyan/yellow/green ombré)
- Black monofin insert for swimming
This Kids Mermaid Swimming Costume turns pool days into underwater fantasy adventures with a rainbow gradient tail that flows from hot pink through purple, cyan, yellow, and green. The swimmable monofin lets your child glide through the water like a real mermaid, while the side-zip tail pants make getting in and out easy even when wet.
The halter bikini top has rainbow tie straps and a double ruffle across the bust, pairing with high-waisted tail pants covered in embossed scale texture. The tail fin flares dramatically with multi-point striped panels that catch the light underwater. Stretchy swimsuit fabric moves with every stroke, and the monofin is labeled anti-breaking for active play. Colour transitions are seamless thanks to gradient dye — no harsh lines, just mermaid magic.
Perfect For
Pool Parties & Beach Outings: A showstopper at summer pool parties, beach trips, or resort holidays where your child wants to swim like a mermaid rather than just splash around.
Mermaid-Themed Birthday Parties: The centerpiece costume for underwater princess parties, fantasy-themed celebrations, or ocean-adventure sleepovers where every guest channels their inner Ariel.
Dress-Up Play & Photo Sessions: Works for fantasy dress-up at home, kindy mermaid parades, or those magical childhood photos that capture the "I'm really a mermaid" moment — even if it's just in the backyard pool.
How to Wear It
Slip the monofin into the tail section first, then step into the pants and zip up the side. Tie the halter top securely at the neck. Pair with a flower crown or starfish hair clip for the full underwater princess look, though those aren't included. Skip shoes — mermaids don't wear them.
Parent FAQs
Q: What size should I order?
A: Check the size chart for waist and height measurements. The tail pants have an elasticized waistband with some stretch, so if your child is between sizes we'd say go with the larger one for longer wear through the summer.
Q: Can she actually swim in this, or is it just for photos?
A: The monofin is designed for real swimming — it's labeled anti-breaking and helps with propulsion. That said, mermaid tails limit leg movement, so supervise closely and only use in environments where your child is a confident swimmer. Not for deep water or ocean surf.
Q: How do I wash this? Will the rainbow fade?
A: Rinse in fresh water after pool or beach use to remove chlorine and salt, then hand wash in cool water with mild detergent. Hang to dry out of direct sun. The gradient dye is printed, so it should hold up, but harsh chemicals or hot water can dull the colors over time.
Q: Is the monofin removable if she just wants to wear the tail for dress-up?
A: Yes — the monofin slips out through the tail opening. She can wear the bikini top and tail pants as a costume on land without the fin, though the tail section will drag a bit at the hem.
Care: Rinse after use, hand wash cool, hang dry. No tumble dryer or bleach.
SHIPPING & RETURNS
Returns Policy
We have a 14-day return policy, which means you have 14 days after receiving your item to request a return.
To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
To start a return, you can contact us at sales@kidsbookweekcostumes.com.au.
If your return is accepted, we’ll send you a return form, as well as instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.
Shipping
We offer Flat Rates $9.8 for Registered Post or $14.8 for Express Post within Australia.

