Skip to content

Leakproof

Leakproof Classic One Piece Swimsuit

The Knix take on a classic. High quality fabric, gorgeous fit and instant confidence.

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Product image

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Jay is a 30F, has 36" hips and wears a Knix size XS+

Leakproof

Leakproof Classic One Piece Swimsuit

The Knix take on a classic. High quality fabric, gorgeous fit and instant confidence.

A timeless style with a fit that we’ve spent years perfecting. Designed with premium UPF 50+ fabric, full butt coverage, removable cups and adjustable straps. Plus, get discreet, built-in protection against leaks. Absorbs about 1 regular tampon worth.

- Absorbs about the same as 1 regular tampon
- Full butt coverage
- Adjustable straps
- Built-in shelf bra
- Removable cups
- Thicker straps for plus cups for added support
- UPF 50+ fabric

Machine Washable: Wash with like colors. Machine wash gentle, do not bleach, do not dry clean, do not iron, lay flat to dry.

Body: 85% Nylon, 15% Spandex
Lining: 85% Nylon, 15% Spandex
FreshFix Technology®Gusset: 93% Polyester, 7% Spandex, 87% Polyester, 13% Spandex, 100% PU, Exclusive of Trims

Additional Product Ingredient Information

Free standard shipping over $100.

Free expedited shipping over $150. Duty-free. (after discounts, before shipping + taxes)

Swim items are eligible for a return or exchange within 30 days of delivery and with tags and original sanitary strip (swim bottoms and one pieces) attached. For sale items with a 20% or more discount you may exchange for another item or store credit.

Contact Us Returns & Exchanges Shipping Product Testing and Safety FAQs Gift Card Balance

Rewards Size Guides Virtual Fittings Resources Store Locations

Story & Mission Sustainability & Philanthropy Careers

Stay in the flow

Give $20Get $20

Privacy Policy
California Privacy Rights
Privacy Choices
Accessibility Statement

How Does Leakproof Swim Work?

swim 1 pc

One-Pieces

Swim Tops

Swimwear Tops

Swim Bottoms

Bottoms

Leakproof Swim

Leakproof

Swim Sets

Sets

Accessories & Apparel

Accessories

Teen Swim

Teen

Bra-Innovations MB

More-Ways-to-Shop DT (2)

More ways to feel unapologetically free

Find an amazing wireless bra to match your Undies. Plus explore our other products, all designed to make you feel so comfortable in your own skin.

Period Underwear BRAS EVERYDAY UNDERWEAR SLEEPWEAR ACTIVEWEAR APPAREL Shapewear Maternity

Help
Returns & Exchanges
Shipping
Size Guides
Rewards
Virtual Fittings
Gift Card Balance
FAQs
Contact Us
Virtual FittingsBOOK NOW
Refer a FriendLearn More
About
Knix FundLearn More
Careers at KnixLearn More
Story & Mission
Why Leakproof?
Virtual Fittings
Store Locations
Ambassador Program
Careers
Rewards
Refer a Friend
Gift Cards
Blog

New
Categories
Shop All New
Best Sellers
Swim
Thigh Saver® Shorts
Sexy Mesh Collection
Featured
Mix & Match to Save up to 25%
Introducing Gabrielle Union
Sport Your Period.
Let's Talk Perimenopause
Gabrielle UnionShop now
Swim CollectionShop Now
Leakproof Underwear
Shop by Absorbency
Ultra
Heavy
Medium
Light
Lightest
Zero
All Underwear
Shop by Style
High Rise
Thong
Bikini
Boyshort
French Cut
Shorts & Boxer Briefs
Thigh Savers
Cheeky
Reusable Pads
Mix & Match to SaveSave up to 25% off
Why Leakproof?SHOP NOW
Bras
Categories
All Bras
T-Shirt Bras
V-Neck Bras
Pullover Bras
Seamless Bras
Sports Bras
Maternity Bras
Find Your Fit
The Bra Guide
Take the Quiz
The Bra GuideLEARN MORE
NEW CitronSHOP NOW
Swim
Categories
All Swim
Swim One-Pieces
Swim Tops
Swim Bottoms
Leakproof Swimwear
Swim Sets
Accessories & Apparel
Teen Period Swim
Shop by Color
Shop All
Feline
Oceana
Mango
Sea Lily
Lush Green
Seashell
Pink Pop
Tropical Punch
Black
Swim CollectionShop Now
Teen Period SwimSHOP NOW
Shapewear
Shop by Style
All Shapewear & Thigh Savers
Thigh Savers
Leakproof Shapewear
Tanks & Bodysuits
NEW Thigh SaversSHOP NOW
Leakproof ShapewearSHOP NOW
Active & Apparel
Active
All Active
Sports Bras
Leggings & Shorts
Active Tops
Swim
Athleisure
Apparel
All Apparel
Loungewear
Sleepwear
Tanks & Bodysuits
Wardrobe Heroes
Maternity
Swim
Accessories
MaternitySHOP NOW
SleepwearShop Now
Teen
Categories
All Teen
Teen Period Underwear
Teen Thigh Savers
Teen Period Swim
Teen Period Kits
Teen Period Activewear
Teen Thigh SaversSHOP NOW
Teen Period SwimSHOP NOW
Sale

Home/
Shop Swim/
Leakproof Classic One Piece Swimsuit

Absorbency: Light

Shop Leakproof Swimwear

Shop Swim

4.4

Rated 4.4 out of 5 stars

78 Reviews

4.4

Rated 4.4 out of 5 stars

78 Reviews

4.4

Rated 4.4 out of 5 stars

Based on 78 reviews

90%would recommend these products

Write a Review (Opens in a new window)

78 reviews

Sort

Elizabeth H.
Verified Buyer
1 week ago
Rated 5 out of 5 stars
Color and fit
The blu color is gorgeous and the comfort and fit had me breakup with underwire suits and miracle suits. Loving the new styles.coming out this season!
Was this helpful?
Dana S.
Verified Buyer
1 week ago
Rated 5 out of 5 stars
Great
Bathing suit is great. The fit is great so comfortable. It’s the best bathing suit I’ve ever had.
Was this helpful?
Janyce B.
Verified Buyer
2 weeks ago
Rated 5 out of 5 stars
Love it!
So happy to see this in real colour! Really happy with the fit too. Thanks KNIX.
Was this helpful?

Loading...

Loading...

Reviews LoadedReviews Added

Leakproof Bikini Swim Bottom

Leakproof Bikini Swim Bottom

+2

Amber has 38" hips and wears a size M

Leakproof High Rise Bikini Bottom

Leakproof Swim Short

Leakproof Swim Short

+1

Jay has 36" hips and wears a Knix size S

Leakproof Sculpt High Rise High Cut Swim Bottom

+3

Maya is a 34F, has 42" hips and wears a Knix size M+

Leakproof Classic One Piece Swimsuit

Adiya is a 36D and has 42" hips and wears a Knix size L

Leakproof Wrap One Piece

Amber has 38" hips and wears a size M

Leakproof Classic Bikini Bottom

Leakproof Deep V One Piece Swimsuit

Leakproof Deep V One Piece Swimsuit