🛒 1 FREE Exchange on Eligible US Orders 📦 FREE Shipping on US Orders Over $85 🖤 25% OFF Full-Priced Swim for Black Friday!

  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!
  • Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!

Penfield High Waist Thong Bikini Bottom | add to cart to get 25% off!

4.8
Rated 4.8 out of 5 stars
16 Reviews
Regular price $69.35
Unit price per
hi 👋 we're onewith - the most flattering swimwear! our swimwear is patent-pending, dig-free, elastic-free, and edgeless, just like your favorite no-show seamless undies.
🖤 25% OFF all full-priced swim for Black Friday, no code needed! discount applies in cart 🖤🛍️
Size
Color:
A dipped high-waist front and a thong back make Penfield an absolute icon. Designed for the woman who wants a daring, cheeky fit that still...
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size & fit info

Customers say this style can run a little big, so if you're in-between sizes, we recommend sizing down.

View our size chart here

shipping & returns

RETURNS

  • 1 free exchange for eligible US orders 🫶
  • 14-day returns available for a fee for eligible US orders 📦
  • items purchased at a discount of 30% or more are eligible for store credit only.
  • items marked final sale are always, you guessed it, final sale!
  • international orders are always final sale. see our full returns policy here.

SHIPPING

  • free standard shipping on US orders over $85 😍
  • priority + express shipping also available! 💨
  • international shipping available, rates and duties calculated at checkout ✈️
  • Shipping Protection, offered at checkout, is HIGHLY recommended! It covers lost, damaged, stolen, and stuck-in-transit packages 👍
product details
  • designed in USA, made in China
  • patent-pending
  • LATEX INFO: we cannot guarantee that the inner grip strip of our suits is entirely free of latex. If you have a latex sensitivity or allergy, we recommend exercising the same caution you would typically use when assessing whether to wear a product that may contain latex.
  • 80% nylon, 20% elastane
  • hand wash only, lay flat to dry
swimsuit care
  • Hand wash in cold water as soon as you can after use (rinsing in the shower is fine!)
  • DO NOT machine wash.
  • Lay flat to dry, do not hang.
  • Do not dry clean, iron, or machine dry (even on a delicate cycle...) as this can, and most likely will, damage your onewith.
  • Hot tubs and chlorinated pools with harsh chemicals can impact the quality and longevity of any swimwear, so it’s best to avoid them if you want to keep your swim in tip-top shape.
  • If you wear your onewith under normal clothes, keep in mind that friction can create pilling/snagging. We prefer to wear our onewith under beach cover-ups/sarongs, which are created to be worn with swim.
  • Sunless tanners, suntan lotions, oils, and harsh chemicals can ruin your onewith - ensure to not get these products in contact with any swim/garments!
  • ships from CT, USA
  • free shipping on US orders over $85
  • 14-day returns
  • 1 free exchange
as seen in

onewith you from the inside out ↔️

our swim has a soft inner grip strip to keep your suit secure...without tight seams.

free shipping on US orders over $85
women-owned + WBENC-certified
size-inclusive (XXS - 4XL)
1 free courtesy exchange eligible on US orders

why choose onewith?

✨onewith ✨ vs. other swimwear

other swim brands
edgeless (no digging!)
no squeezing (elastic-free!)
no hidden seams inside
raw-cut (lays-flat on the body!)
inner grip inside to keep secure
made with 2 layers of fabric

☝️ frequently asked questions

the most commonly asked Qs about our swim that fits like undies ⬇️
  • please take our size quiz! it's the pink button that says 'CLICK HERE to find your size.' that is on every single product page on our site.

    you only need to take it once, and your best size will automatically display for each product on our site, depending on how that product runs.

    if you still want help in finding your size, reference our size guide here

    additionally, chat us on-site (quickest!) or DM us on IG and we can help you out.

  • We offer 1 free exchange on eligible US orders so that you can find your best onewith size.

    Returns are available for a $12.50 fee per order (additional fee will apply if you're returning more than 3 items).

    US orders purchased at a discount of 30% or more are eligible for return for store credit ONLY. no refunds or exchanges.

    International orders are ALWAYS final sale.

    You may return/exchange your eligible order within 14 days, the 14-day window begins the day of carrier-confirmed delivery. 

    Read more about the onewith Return Policy here.

    ⚠️ NOTE: ITEMS MARKED FINAL SALE + MYSTERY BUNDLES ARE ABSOLUTELY, POSITIVELY FINAL SALE. No returns, no exchanges, no exceptions. 

  • onewith = 2 layers of normal swimwear fabric, just like any other swimwear. people tend to think our swim is either 1 layer of fabric, and/or super thin, like no-show undies. that is not true! again, our swim has 2 layers of fabric. It's just bonded together, not sewn with tight seams, which gives it a sleeker appearance that people may read as "thin." While we can't guarantee our suits are frontal-wedgie-free, so-to-speak as every person's anatomy is different, we can say that there is no reason why our suits would cause 🐪toe more than any other swimwear.

  • yes, all of our bikini tops + one pieces have removable bust cups that you can leave in, or take out!

  • we get it, the itch to get your swim that doesn't dig in ASAP is real! luckily, we do offer an Express shipping option if you do need it ASAP. otherwise, we offer free standard shipping on US orders over $85. all orders with standard shipping ship from our Connecticut, USA warehouse within 2-5 business days of receiving your order.

  • ALL onewith suits feature our inner grip strip, which keeps the suits secure without the use of tight seams or elastic that digs. the inner grip strip is super soft and flexible.

4.8
Rated 4.8 out of 5 stars
Based on 16 reviews
Total 5 star reviews: 12 Total 4 star reviews: 4 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
100%would recommend these products
16 reviews
  • JH
    Jennifer H.
    Verified Buyer
    Penfield High Waist Thong Bikini Bottom | NEW & IMPROVED FIT!
    Reviewing
    Penfield High Waist Thong Bikini Bottom | NEW & IMPROVED FIT!
    I recommend this product
    Rated 5 out of 5 stars
    1 month ago
    AMAZING

    I have waited so long for a pair of swim bottoms to fit like this and to actually be a flattering thong without making me feel like I’ve been tied up with butchers string and things popping out where they shouldn’t. I’m in between sizes right now and I’m losing weight pretty quickly, but it feels great to know that I can sit the waist up higher or lower depending on how I’m feeling and knowing it won’t slip

    O Profile picture for onewith
    onewith
    1 week ago

    Thank you so much for your wonderful review, Jennifer! We're over the moon to hear our Penfield thong bikini bottom exceeded your expectations in both fit and coverage. It's always been our goal to provide swimwear that makes every body feel beautiful, confident, and comfortable. Enjoy your onewith :)

  • LB
    Liz B.
    Verified Buyer
    Penfield High Waist Thong Bikini Bottom | NEW & IMPROVED FIT!
    Reviewing
    Penfield High Waist Thong Bikini Bottom | NEW & IMPROVED FIT!
    I recommend this product
    Rated 5 out of 5 stars
    4 months ago
    Truly fits like comfy undies

    I have struggled for years to find a bathing suit bottom that fits my booty and larger thighs, and goes high enough so that I feel somewhat covered up. These bottoms fit like my comfiest underwear and don’t dig in like most other bathing suit brands do. I highly recommend the high waist thong for any curvy gurlies who are sick of unflattering bathing suit options digging into your butt and thighs. These are super sexy and super comfortable. 🔥🔥🔥

    O Profile picture for onewith
    onewith
    4 months ago

    Hi Liz, thank you so much for your incredible review! We're thrilled to hear you've finally found the perfect, comfy-yet-sexy fit with our Penfield! We so appreciate you sharing and your recommendation for other women with a similar body type. Enjoy your onewith!

  • LF
    Lacey F.
    Verified Buyer
    Penfield High Waist Thong Bikini Bottom - Buzzin | FINAL SALE
    Reviewing
    Penfield High Waist Thong Bikini Bottom - Buzzin | FINAL SALE
    I recommend this product
    Rated 5 out of 5 stars
    5 months ago
    Perfect Bottoms!

    Excellent quality and fit. Will most definitely purchase more!

    O Profile picture for onewith
    onewith
    4 months ago

    Hi Lacey, thank you so much for your amazing 5-star review! We're thrilled to hear the quality and fit of the Longshore exceeded your expectations. We can't wait to have you shop with us again soon!

  • HH
    Heather H.
    Verified Buyer
    Penfield High Waist Thong Bikini Bottom | NEW & IMPROVED FIT!
    Reviewing
    Penfield High Waist Thong Bikini Bottom | NEW & IMPROVED FIT!
    I recommend this product
    Rated 5 out of 5 stars
    6 months ago
    Great fit

    This bottom is super comfortable and fits just like no show underwear!

    O Profile picture for onewith
    onewith
    5 months ago

    Hi Heather, thank you so much for this review! We're so glad to hear you found the Penfield to fit just like your favorite no-show undies, and that it's super comfortable. Enjoy your onewith 🌊

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