10 Best One-Piece Swimsuits, Tested and Reviewed

Avoid the strap tan lines with this strapless ruched swimsuit. Earning perfect marks across the board from one of our GH testers, this one-piece bandeau has all the features we love in a high-quality swimsuit: the fabric offers built-in UPF 50 sun protection, you can add straps for more support, and the cup padding is removable.

A tester noted that you cannot dive headfirst into the pool without the straps on for this suit, but the strapless design otherwise stayed in place (so maybe opt for another bathing suit if you plan to dive or surf!).

One GH editor loves the simple, ruched design of this long-lasting suit and has worn it summer after summer. "It's classic and ultra flattering...timeless really," said another tester. We also like that the size range is extensive, including regular and long torso options, so you can find your perfect fit.

When you need a swimsuit ASAP, Amazon Prime's fast shipping has you covered. Cupshe is one of our favorite swimsuit brands on Amazon for its affordable price points, high quality, extensive size range, and variety of color options. This one-piece swimsuit features a deep-V neckline, a high-cut bottom, and a ruched stomach for a stylish, tummy-control design.

The straps are thin underneath the ruffles, which could feel less supportive for larger chests or dig into the skin, but they are adjustable. I wear a D/DD and felt secure, even with the plunging neckline. The lace-up detail in the back really held everything in place. Our GH testers also loved Cupshe suits: "I've worn swimsuits that cost three times as much as this one, but I'm always reaching for it on a pool day," said one tester who tried a bikini from the brand.

My one issue with the swimsuit: Cupshe's material isn't as high quality as other brands'. It's not going to fall apart after a couple of wears, but it has a rougher feel.

In our roundup of the best swimsuit brands, Andie was named the best brand for one-piece swimsuits, though they are on the pricey side. Like other suits from this company, Andie's Almafi One Piece offers classic and long-torso size options to an already extensive size range (XS–3X). That means if you're 6 feet tall, you can rock a one-piece swimsuit without needing to size up (the suit will actually fit well without looking baggy or digging into your skin!). If you opt for classic black, you can even choose the bottom coverage level: medium, full, or cheeky.

One of our GH analysts reported that this swimsuit has a slightly compressive material that's comfortable and less restrictive than some other smoothing styles she has tested. There is no underwire, but the suit comes with removable cups and adjustable straps for support. The swimsuit straps are thicker for sizes 2X and 3X, but if you wear a smaller size and have a larger chest, the straps may dig in.

We also love that you can choose from 14 bright colors and patterns that vary across fabrications, like flat and ribbed knits.

It's hard to beat the size range of this swimsuit, available in sizes 8 to 34, so you can find your perfect fit. Featuring a longer panel of material in the front section, this one-piece swimsuit gives the appearance of a sarong. Cute yet functional, the sarong portion adds extra coverage, and the front stomach area is lined with Power Mesh fabric for tummy control and smoothing.

The elastic underband and built-in cups provide support without a traditional metal underwire. One tester with DD-cups was impressed by the supportive feel of a Swimsuits for All top without underwire. Keep in mind that some testers and I have found Swimsuits for All styles to run a little small, so be sure to use the brand's sizing tool to choose your best fit.

Summersalt is a favorite brand among our editors, and the Sidestroke one-shoulder bathing suit is one of its most popular styles (it has sold out dozens of times!). It is made of a compressive fabric that shapes the bodice without feeling too tight. The design also features a colorful, diagonal pleated effect across the front and a unique cut-out back. Plus, there are tons of sizes (including a long-torso option for taller folks) and color variations to choose from.

One thing to be aware of is the suit's lack of lining or modesty cups, but some of our analysts with larger bust sizes said the suit felt secure and stayed in place while wearing.

This sleek one-piece swimsuit from Lands' End was rated "most flattering" by product testers in one of our Lab's rounds of swimsuit testing, thanks to its firming, slimming fabric. In our Lab tests, the fabric held up to repeated washing and kept its color well after repeated washing and exposure to chlorine and sunlight. This means the suit should be long-lasting and withstand washing, chlorine, saltwater, UV rays, and wear summer after summer.

"Hands down, Lands' End offers the best bathing suits I've been able to find!" one tester said. While the smallest size starts at 6, the size range is impressive, going up to 18 with regular, petite, plus size, long torso, and long torso plus options. Additional sizes are available up to 24 when you select plus size or long torso plus, and you can choose from regular, D, DD, and DDD cup sizes, making it perfect for women with larger busts.

According to testers, the swimsuit runs a bit tight due to the compressive material used to smooth and shape the stomach. If you're between sizes or prefer something less restrictive, it may be a good idea to size up.

RELATED: The Best Swimsuits for Large Busts

A swimsuit with a fun cut-out like this one from Old Navy combines the security of a traditional one-piece with the more skin-forward look of a bikini. Old Navy's swimsuits are always priced affordably, but I suggest waiting to buy until there's a sale for an even better deal—the brand is always having one!

This swimsuit is packed full of trendy elements, like a monochromatic buckle, a deep neckline, and a textured pique material, that are sure to stand out on the beach. The swimsuit comes in a wide range of sizes—XS to 4X—but may not be ideal for those with long torsos or large busts. Because of the cut-out right below the chest without there being an underwire or built-in band, you might find that your breast tissue spills out below the cups, creating some unwanted bottom cleavage (I did!). The style is better suited to smaller chests.

Whether you're training for a triathlon, want to swim laps for an exercise that's easy on the joints, or your teenager needs a new competitive suit, this pick is one of our favorite styles from Speedo, a trusted brand for water sports. Its ProLT swimsuit is made with durable fabric that Speedo claims is resistant to chlorine, sand, and sunscreen.

The fully lined suit comes in a few solid color options, and the compressive material is supportive without underwire or padding. We love that this suit is designed to stay in place thanks to the cross straps in the back.

Keep in mind that athletic swimsuit sizing is different from regular swimsuit sizing. Check the size guide for your measurements, but here's an example: if your waist is 25 inches, your size on the Speedo size guide would be 28.

However, this pick is constructed with compression fabric to enhance athletes' performance and reduce water resistance, so it runs on the smaller side. One of our editors who swims non-competitively opts to size up from the brand's recommendation for a less-tight overall feel. If you plan to wear this suit for more casual activities, we recommend going up by a size or two.