What Should You Wear Under Your Swimsuit?

Swimming can be a real confidence tester for many of us. Sure, we all love the weightless free feeling of gliding through cool water on a hot summer day, but wearing a swimsuit can sometimes make you feel self conscious and exposed.

Is there anything you can wear under your swimsuit to help with this or are you meant to wear them with nothing underneath?

Swimsuits are designed to be worn with nothing underneath. The fabric is thick, quick-drying, and can withstand harsh chemicals like pool chlorine. The snug fit reduces drag in the water and stays in place as you move and swim. Swimsuits are usually lined, so underwear is not necessary. 

There are some exceptions. There is no rule that says you can't wear something underneath your swimsuit if you want or need to it's just not the norm.

Let's cut to the nitty-gritty so you can stride towards the pool confidently this summer. 

What Should You Wear Under Your Swimsuit?

Ideally you shouldn't wear anything under your swimsuit.

The challenge with wearing something under your swimsuit is that although it may feel more comfortable while you are dry the moment it gets soaked it may become unsightly and it could start chaffing.

On top of that most other garments don't dry as quickly as your swimsuit so the material will feel damp and uncomfortable pressed tightly against your skin.

Swimsuits also tend to cling to your body so any clothing worn underneath a swimsuit will show through the swimsuit.

Swimsuits are universally created to act as both under and outerwear so you don't need to wear anything under them.

Going commando under your swimsuit is normal as there should only be one layer of stretchy, quick-drying fabric between the water and your skin.

Most swimsuits have a lining in appropriate places for comfort, hygiene and modesty and the fabric is designed so it will not become see-through when it's wet.

The main exception is ladies with bigger busts who need a bit more support than their swimmers provide. For these people wearing a swim bra under your swimsuit can be a good option and there are a few varieties that won't make it look like you're wearing a bra under your swimmers, it'll just look normal.

If you're looking for increased modesty then wearing a rash shirt over your swimmers is a good idea. It'll provide UV protection from the sun but will also cover you up and make you feel more comfortable if you don't want to show everything to everyone on the beach.

If you're still not sure check out our guide on rash guards vs swimsuits to help you decide which one you should wear.

Do Swimmers Wear Underwear Under Their Swimsuit?

Swimmers need to be extremely streamlined to reduce drag. The less weight they have on their bodies pulling them back the faster they will be able to move through the water.

Professional swimmers wear thin tight-fitting swimsuits that are like a second skin and they don't wear anything underneath these swimsuits. Even male swimmers wear skin-tight swimsuits. They never wear anything under these swimsuits. 

Do Girls Wear Underwear Under Their Swimsuit?

Most girls only wear underwear under their swimsuits when they try them on in the fitting room. Once it is purchased and has one owner there is no need to wear anything under a swimsuit because it is specifically designed to cover what it should, stay in place, and dry quickly. 

Swimsuits are able to hold their own alone at the pool because they are constructed stronger, thicker, and more water-resistant than regular underwear. Sensitive areas have a lining so adding another layer below the swimsuit would essentially be a third layer. 

Do Guys Wear Anything Under Swim Trunks?

Some guys do but most guys don't!

Many swim trunks have a soft mesh liner which not only holds everything in place but provides a protective layer between the wearer's skin and the hard outer fabric.

Trunks with lining do not need additional undies because the lining acts as a quick-drying underlayer. 

Not all swim trucks have liners so it is up to the individual to decide if they want to wear a layer underneath if they are wearing an unlined version.

Surfers often prefer not to wear nothing at all under their wetsuit, or at most they'll wear trunks but nothing else.

Unless they are made from thick fabric which may feel stiff the swim trunks may cling to every nuance of the wearer's body when they are soaked.

If you don't feel comfortable just wearing trunks as you feel it is too exposing or your bits tend to show when they get wet then instead of wearing something under your trunks you should wear board shorts over your trunks.

Why You Shouldn't Wear Anything Under Your Swimsuit

Regular underwear is usually made from materials like cotton, so it is soft and breathable. These materials tend to be super absorbent and slow to dry. Wearing any non-swim fabric material below your swimsuit will be uncomfortable, especially once it gets wet.

Adding regular underwear under your swimsuit will result in having a waterlogged layer that won't dry quickly stuck between your skin and the swimsuit. In addition, swimsuits tend to be figure-hugging for comfort so adding anything below may be visible. 

If modesty is your main concern it is a far better idea to wear something over your swimsuit rather than under it. Rash guards are perfect covers for swim bras so you can choose one that offers the support you need and add a gorgeous, versatile, quick-drying rash guard and you will be good to go. 

Another option is a wetsuit which will help to keep you warm and you can still look great in a wetsuit.

Board shorts or compression shorts are a great option if you want to cover your thighs. You will be able to enjoy water activities confidently and your swimwear will look appropriate and dry quickly. 

Can You Wear A Menstrual Pad Under Your Swimsuit?

You don't want to miss any of the fun just because it's that time of the month!

You can most certainly wear a thin sanitary pad under your swimsuit when you are on your period. Just make sure you purchase the right one that fits your swimsuit well and doesn't show.

However, many women prefer using a tampon or menstrual cup as these won't soak up water from the ocean or pool if you go swimming. But this isn't always possible for everyone.

Of course pads and water don't always go well together because pads absorb moisture. So as soon as you finish swimming, wrap a towel around your waist and quickly slip a new, dry pad in place.

You may have a bit of trouble sticking it onto the wet swimsuit. 

There are a few things you should be aware of before using a sanitary pad under your swimsuit: 

  • You cannot use pads with wings because they will be visible on the outside
  • Choose a dark color swimsuit. That way, if there is a tiny leak, it will be less visible as you leave the water.
  • A soaked sanitary towel will feel cold, soggy, and uncomfortable when you come out of the water so wrap a towel around your waist and quickly go slip in a dry one. 

A good idea when wearing a sanitary pad under your swimsuit is to wear a colorful pair of board shorts.

It won't look out of place and you can swim much more confidently and have fun without worrying about your pad.  

Can A Bra Be Worn Under A Swimsuit For Extra Support?

If your favorite swimsuit does not offer enough support for your bust but you really want to wear it, you may be tempted to wear a bra under it to provide lift.

Although this approach can work perfectly if you intend to stay dry the challenge comes when you hit the water. 

Regular bras are not made of quick-drying fabric and they are quite delicate. So besides possibly damaging your bra it will feel uncomfortable when it is waterlogged.

However, if you need the extra support to feel confident and look good then you can wear a bra under your swimsuit.

If you want to wear an extra bra for support and you will be getting wet it's a great idea to shop for an inexpensive swim bra.

These are usually the top of a two-piece that are readily available. It will last longer because it is made from a swim-friendly fabric that will dry faster. 

Can People Tell If You Wear A Swimsuit Under Your Clothes?

Unless the swimsuit is visible because of its design or bold color, there is no way that someone will be able to tell that you are wearing a swimsuit under your clothes. Using your swimsuit as a stand-in for your regular underwear is not a good idea because it can wear out or get damaged. 

Swimsuits are far more expensive than regular underwear. They are made from much thicker, stretchy nylon spandex material, which is fast drying and intended as outerwear. 

Wearing your swimsuit in place of regular soft, breathable underwear may also cause skin irritation or make you feel uncomfortable. However, no one besides you will know that you are wearing your swimsuit when it is covered with clothing. 


Swimsuits are designed to function as underwear and outerwear, so you should not wear anything underneath. The fast-drying, durable fabric will allow you to move easily in the water and feel comfortable when you are back on dry land. If you need additional lift and support for your bust under your swimwear, some options are available, but regular underwear is usually not a good option.