The One Black/Red

US$71 USD US$177  save 60%

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This classic one piece is engineered to sculpt your body and support your bust just like shape wear. Recycled Italian sculpting fabric, seamless construction, hidden in built underwire bra and a scooped low back makes this style an essential for D+ women.

Mercy wears size 34G
Fits true to standard bra sizes
Adjustable straps
Low scoop back
Hidden in-built underwire bra
Fully lined with second skin lining
Recycled Italian sculpting fabric

78% of our Italian fabric is made from recycled waste, like fishing nets, fabric scraps, carpet flooring and industrial plastic from landfills and oceans all over the world.

2 x more resistant to chlorine
2 x more resistant to suntan oils & creams
Excellent UV protection
Unrivalled shape retention
Care: rinse after chlorine & hand wash cold

30 day returns

Full priced items

Size Exchange:
Full priced and sale items up to 60% off, Australia only

Store Credit:
Sale items

Final sale no returns:
Items 60% off and above

Full returns policy here.

Free express worldwide shipping on orders over AU$200 / US$155

Australia Post Express (1-2 business days)
Orders over $200 AUD: FREE
Orders under $200 AUD: $10 AUD

United States:
FedEx Priority (4-6 business days)
Orders over $200 AUD: FREE
Orders under $200 AUD: $25 AUD

New Zealand:
Australia Post Express (2-4 business days)
Orders over $200 AUD: FREE
Orders under $200 AUD: $15 AUD

FedEx Priority (4-6 business days)
Orders over $200 AUD: FREE
Orders under $200 AUD: $25 AUD

Shipping timeframes are estimates only. Full shipping policy here.


Customer Reviews
4.6 Based on 82 Reviews
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Filter Reviews:
Arabella C.
  • Size Purchased 10E
Fits like a dream

The perfect combination of support + sexy. I can jump in the surf and don’t need to worry about anything falling out (!). Love the colour too - a really beautiful rich red.

  • Size Purchased 32FF
So good, listened to the sizing advice from the fit quiz

I'm a 30G bra size but my bottoms are a UK/AU 12 and so I was worried about finding a one piece that would work for my whole torso--the fit quiz suggested a 32FF and it worked really well for me! I wish I had gotten this in red instead of black but I honestly think I'll just buy that too eventually haha. It was certainly worth the price, I felt quite cute and secure in it.

Sascha B.
  • Size Purchased 30FF
Perfect fit

gorgeous one piece! really supportive but completely comfortable the hidden bra is perfect and totally invisible. Best swimsuit i’ve owned in years

  • Size Purchased 34dd
The One

I got the one piece as well as the Base in the same size (34dd). The base bikini is AMAZING. The one piece is good--but the torso feels a bit short (I'm not a tall or long torso'd person). Its kinda rides up the rear--I feel like I could have sized up, but I'm not sure in what way...maybe a 36dd? I'm keeping it anyways ¯_(ツ)_/¯

Form and Fold

Hey! The One does have briefer rear coverage so if you're after a little more coverage sizing up will definitely help with that! Sounds like a 36DD would be perfect for you :)

  • Size Purchased M
Ombre swimsuit

The pattern of the swimsuit was absolutely beautiful, and it seemed very well made. Unfortunately it was far, far to short in the body for me, (5’6”, size 12) so I had to return, and, due to incorrect paperwork provided with delivery, I’m having a really hard time reclaiming import taxes on international shipment. Hopefully these issues can be ironed out as the product looked lovely.

How It Supports You

How It Supports You
A classic shape with a scooped open back and brief to mid rear coverage
Recycled Italian fabric feels like a second skin and sculpts the body like shape-wear
Hidden in built underwire bra and adjustable straps for the ultimate support

Easy and simple, like it should be.

Fit Quiz

Find the right size and style in 90 seconds with our fit quiz designed by our team of expert Fit Specialists.

Fit Specialists

When your order arrives, our team of Fit Specialists are here to help with any size or style questions.

30 Day Refunds

Try your order and if you don't love it for any reason we'll take full-priced items back for a refund.