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Period Swim Sport One-Piece
Period Swim Sport One-Piece
368 ReviewsBundle & Save

Period Swim Sport One-Piece

$88.00
$88.00USDBuy 3+ SAVE 15%, Buy 5+ SAVE 20%
✓Absorbs about 2-3 regular tampons✓Medium coverage✓Sporty scoop neckline✓Premium UPF 50+ fabric✓Machine washable
Absorbency: Light
Compare to Pads & Tampons

Light

• Ideal for lightest period days, spotting, sweat and discharge.

  • about 1-3 tsp
  • about 1-3 pantyliners
  • about 1-3 regular tampons
  • about 0.5 menstrual cups

Moderate

• Ideal for medium period days, discharge and sweat.

  • about 4-8 tsp
  • about 1-1.5 regular pads
  • about 2-4 super tampons
  • about 0.5-3 menstrual cups

Heavy

• Perfect for overnight protection or your teens heaviest days when changing into a fresh pair might not be convenient.

  • about 8-14 tsp
  • about 1.5-3 regular pads
  • about 4-7 super tampons
  • about 1.5-3 menstrual cups

Ultra

• Our longest front-to-back liner, designed for their heaviest flow days and overnight protection.

  • about 15-20 tsp
  • about 1.5-2.5 super pads
  • about 7-11 super tampons
  • about 2-3 menstrual cups
Color
Size
True to Size
Size and Fit Guide

Size Guide

KT SizeBandHips (In)Kids Pant SizeAdult Pant Size
XXS23 3/4 - 25 1/425 - 277---
XS25 1/4 - 26 3/428 - 308 - 10---
S26 3/4 - 28 1/431 - 3412 - 1400 - 2
M28 1/4 - 29 3/435 - 3816 - 204 - 8
L29 3/4 - 31 1/239 - 42---10 - 14
XL31 1/2 - 33 1/243 - 46---16 - 18
XXL33 1/2 - 35 1/247 - 50---20 - 22

How to Measure

Waist
Measure around the narrowest part of your torso, usually just above your belly button. Keep the tape snug and level, but not tight. The number where it meets is your waist measurement.

Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.
Shipping

Processing Timelines

Please allow 1-2 business days for our warehouse team to pack and ship your order. During peak periods such as sales, holidays and product launches, please allow up to 4 business days for us to process your order. Once an order is placed, we cannot guarantee any address updates, order changes or cancellations. Orders placed on Friday after 1PM will not be shipped until the following Monday.

Most orders will ship from a single warehouse. However, we occasionally ship from a combination of warehouse locations, so you may receive your order in multiple parts. If items from your order ship in separate packages, we’ll send you tracking information for each package when it becomes available.

Delivery Timelines

For the most up to date delivery time estimates, please refer to the shipping timeline at checkout. All transit times are measured in business days which are Monday-Friday, excluding holidays.

Please note, all shipping timelines are estimates and are not guaranteed.

Canadian Orders

Orders within Canada will be shipped with Canada Post or Purolator based on your address and carrier availability.

Standard Canadian shipping is free on eligible orders over $80 CAD*. Orders under $80 CAD are $12 CAD for standard shipping. Orders delivering to NWT, Nunavut, and Yukon under $100 CAD* are $20 CAD for standard Canada shipping.

*After discounts, before shipping and taxes

Return Policy

Return policy varies by product, please check if your item is refund or exchange eligible by viewing our full policy here.

“My daughter is 12 and just started her period. She is a competitive swimmer. This bathing suit has been the solution for all of her needs. She is confident going to practice in this suit. It's good quality and easy to care for." ”

'- Jane V S.

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Swim Style

A sporty one-piece style featuring removable cups and an open racerback for added mobility.

Worry-Free Protection

Discreet, built-in protection that absorbs about 2-3 regular tampons worth.

Sun-Smart Protection

Premium UPF 50+ fabric helps shield from UV rays while you relax, swim, and play.

Machine Washable

Wash with like colors on a cold cycle using a mild detergent. Do not bleach, dry clean, or iron. Lay flat to dry.

Fabric

Body: 85% Nylon / 15% Spandex; Lining: 85% Nylon / 15% Spandex; Gusset: Fresh Fix Technology®, Polyurethane Film

FREE Shipping on orders over $80

Eligible for return or exchange within 30 days of delivery, in unworn condition with tags and sanitary strip (swim bottoms and one-pieces) attached.
 

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Ordered

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Order Ready

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Leakproof swimwear innovation
LEAKPROOF SWIM WORKS IN LAYERS

Built-in protection that feels like nothing at all.

Looks just like regular swimwear. Non-swelling liner and patented no-show design.
Soft Top Layer

Top Layer

Smooth and comfortable liner in swimsuit fabric.
Middle Layer

Middle Layer

The absorbent layer holds about 2-3 regular tampons worth of blood.

Your questions, answered.

Our period swim bottoms have a triple-layer gusset that absorbs your flow and locks in leaks, in and out of the water. And when you throw them in the wash with detergent, everything releases through the top layer so your swimwear comes out fresh and clean. Your other clothes will be totally fine too, we promise.

Here's how the three layers break down:

Layer 1 is a silky-smooth top layer that sits right against the skin.
Layer 2 is a super absorbent middle layer built with our leakproof tech that holds up to 1–3 tampons worth of blood.
Layer 3 is a waterproof outer layer that prevents any leaks from showing through.

Not always! On lighter days, the swimwear can handle it solo. On heavier days, pairing it with a tampon or menstrual cup gives extra peace of mind. Every period is different, go with whatever feels most confident.

Machine wash cold and lay flat to dry. Skip the bleach, iron, and dry cleaning.

100%! The leakproof liner is completely undetectable, so it looks and feels just like regular swimwear. No one will know but you.

Our styles are made to fit teen and tween bodies. For adult sizes in period swimwear and leakproof activewear, head over to Knix.ca.

Yes! Returns and exchanges on activewear are accepted within 30 days of delivery, as long as the tags are still on.

Customer Reviews

4.5 ★★★★★ Based on 368 reviews
Reviews Summary ✧

Customers say this swimsuit is comfortable and well-made, with many daughters wearing it even when not needed for protection. Parents appreciate how it gives their children confidence to continue swimming activities without worry. The suit looks and feels like regular swimwear, making it suitable for competitive swimming, swim team practice, and recreational use. Many reviews mention excellent quality and good fit, though some note sizing can run large or small depending on body type. A few customers experienced issues with padding shifting during diving or the suit becoming saggy when wet. Some wish for more coverage on the bottom or back, and occasional fading in chlorinated pools was mentioned.

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Keywords
Fit Comfort Protection Quality Design Confidence Performance
Rating
★ ★★ ★★★ ★★★★ ★★★★★
368 reviews
Larissa P. Verified Buyer ●
Period Swim Sport One-Piece
Black / S
★★★★★
1 week ago

Beautiful swimsuit

Bought it for my daughter - looks beautiful and high quality.

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Janine F. Verified Buyer ●
Period Swim Sport One-Piece
Black / S
★★★★★
2 weeks ago

Very nice swimsuit

Bought the black version for my 11 year old. She just got her period so it seemed to work well for that purpose. She likes the fit of the swimsuit and I like that it has a proper bra.

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Christine R. Verified Buyer ●
Period Swim Sport One-Piece
Black / M
★★★★★
3 weeks ago

Saved the summer

My Swim team daughter appreciated this, this summer!

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Diane
Period Swim Sport One-Piece
Black / S
★★★★★
3 weeks ago

5 Stars

Fantastic swim suit for my daughter

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Helena D. Verified Buyer ●
Period Swim Sport One-Piece
Black / S
★★★★★
1 month ago

One piece swimsuit

My daughter loves this one piece. Its very comfortable and very flattering.

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Lianne B. Verified Buyer ●
Period Swim Sport One-Piece
Shady Blue / S
★★★★★
1 month ago

This Swimsuit is My Favourite!!

This swimsuit fits me so well, is so nicely made and makes me feel good about swimming on my period!!

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