What swimwear should a one-year-old wear?

Your one-year-old is ready to splash, play, and explore the water, but what swimsuit should they wear? As a responsible parent, keeping your baby safe is just as important as letting them have fun. At this age, your little one needs swimwear that does three things: protects their skin from UV rays, keeps them comfortable in varying water temperatures, and makes the inevitable diaper changes quick and stress-free.

The best swimwear for one-year-olds combines UPF 50+ sun protection, easy-on designs with full-length zippers, and high-visibility colors that help you spot your child. As children’s swimsuit experts, SwimZip has the answers to all your questions, including helpful recommendations on what swimwear to get, what to avoid, and how to practice total sun safety with your adventurous baby.

Best one-year-old swimwear at-a-glance

Full-body sunsuits

Full-body sunsuits are the gold standard for one-year-old swimwear. These one-piece suits feature long sleeves and full-length legs that cover the majority of your baby's skin, providing maximum protection from harmful UV radiation.

Quality sunsuits include UPF 50+ fabric that blocks 98% of UVA and UVB rays. SwimZip's baby sun protective swimwear carries the Skin Cancer Foundation Seal of Recommendation, giving you confidence that your child's skin is genuinely protected.

Full-length front zippers transform diaper changes from a wrestling match into a 30-second task. Look for designs with zipper garages that protect your baby's delicate neck and chin from pinching. SwimZip's signature zipper design runs from neck to leg, so you can change diapers without entirely removing the suit.

Many baby sunsuits also feature integrated swim diaper pockets that hold reusable swim diapers securely in place. Combined with tagless construction and flat seams, these suits prevent irritation during all-day wear.

Best for: All-day beach trips, pool parties, lake outings, any extended water play

🏊 Shop SwimZip's UPF 50+ baby swimwear.

Rash guards + trunks

Pairing rash guards lets you customize your child’s coverage and diaper access. This combination offers partial sun protection—excellent coverage for the torso and arms, though legs remain more exposed to UV rays.

Long-sleeve rash guards provide the most comprehensive upper-body protection. The tight weave of UPF 50+ fabric blocks harmful rays while remaining lightweight and breathable. Your baby gets freedom of movement without sacrificing protection.

Stick with zipper rash guards when shopping for one-year-olds. Instead of struggling to pull a wet shirt over your baby's head, you simply unzip and slide it off. Look for zipper garages at the neck that prevent skin pinching.

Pair rash guards with boys' swim trunks, or choose euro shorties for a snug, compression fit. Separate pieces make it easy to remove the bottoms for diaper changes without adjusting the top.

Best for: Maximum flexibility, easy diaper changes, mixing and matching styles

🏊 Find toddler rash guards with easy-zip designs and UPF 50+ protection for your little swimmer.

Rash guards + one-piece

Layering a rash guard over a one-piece swimsuit provides sun protection without committing to a full sunsuit. This combination shields arms and torso while the one-piece protects the core.

This setup provides excellent temperature regulation. In cooler water, the double layer of fabric keeps your baby warmer without overheating in the sun. You can remove the rash guard when conditions warm up, giving you all-day adaptability.

Diaper changes vary by brand with this combination. SwimZip toddler one-pieces feature snap buttons at the crotch for easy diaper access without removing the suit.

Short-sleeve rash guards offer a lighter layering option for very warm conditions. Keep in mind that exposed forearms will need sunscreen application and more frequent reapplication after water play.

Best for: Enhanced protection with styling flexibility, transitioning between water temperatures

One-year-old swimwear features to look for

UPF 50+ sun protection

UPF (Ultraviolet Protection Factor) 50+ is the highest sun protection rating available for fabric. Unlike regular clothing that allows UV rays to penetrate, UPF 50+ clothing blocks about 98% of UVA and UVB radiation.

Babies have thin skin with less melanin than adults, making them more vulnerable to sun damage. A single severe sunburn in childhood can double the lifetime risk of melanoma, the deadliest form of skin cancer.

The Skin Cancer Foundation Seal of Recommendation indicates that swimwear has been rigorously tested and meets strict criteria for UV protection. As a recommended swimwear company, SimZip swimwear is an investment in genuine protection backed by dermatologists.

High-visibility colors for water safety

Neon colors like bright orange, lime green, hot pink, and electric yellow create maximum contrast against water backgrounds.

Studies show that bright, solid colors are easier to spot than pastels, patterns, or dark tones. In murky lake water or crowded public pools, a child in neon stands out. Those precious seconds can make the difference in preventing accidents.

High-visibility swimwear looks good and keeps your child safe. SwimZip's neon collection includes sunsuits, rash guards, and swim trunks in high-visibility shades that help you maintain visual contact with your baby at all times.

Avoid white swimsuits or light blue swimwear, which tend to blend with pool surfaces and create camouflage effects underwater. Similarly, black swimsuits are hard to see and absorb more heat from the sun.

Full-length zippers for easy diaper changes

Anyone who has wrestled a wet, sandy baby out of a pullover swimsuit knows the value of a full-length zipper. SwimZip's signature zipper runs from the neck all the way down to the leg for easy wardrobe and diaper changes.

The zipper garage at the top protects your baby's neck and chin from pinching or chafing. This covered zipper pull keeps the metal off your child’s skin, even during vigorous play.

Proper fit and sizing

The right fit balances snugness with comfort. Swimwear that's too loose offers less UV protection because gaps allow sunlight to reach the skin. Baggy suits also create safety hazards by catching water and weighing your baby down.

Swimwear that's too tight restricts movement and causes discomfort. Your baby should be able to crawl, kick, and move freely without the suit riding up or pulling at the shoulders.

Most one-year-olds fit 12 to 18-month sizing, but always check the manufacturer's size chart. SwimZip's baby swimwear is cut for this age group's proportions.

Size up if your baby is between sizes or has a longer torso. It's better to have slightly extra room than a suit that's uncomfortably snug or restrictive.

Tagless and flat-seam construction

Babies have sensitive skin that reacts to friction and rough textures. Sewn-in tags can irritate the back of the neck, especially when wet fabric rubs against them.

Tagless designs print size and care information directly onto the fabric, eliminating this irritation source. SwimZip's baby swimwear uses this approach to keep your little one comfortable during extended wear.

Flat seams lie smooth against the skin instead of creating raised ridges. This construction technique prevents chafing in high-friction areas like underarms, inner thighs, and the neck.

Chlorine and salt resistance

Pool chlorine and ocean salt water degrade swimwear fabric over time, causing fading, stretching, and loss of elasticity. More concerningly, this degradation can reduce the fabric's UPF protection capacity.

SwimZip's chlorine-resistant swimwear maintains its protective properties and vibrant colors throughout multiple seasons. Our quick-dry fabric also prevents mildew and odor buildup that can occur with slow-drying suits.

Follow proper swimsuit care instructions to get the most out of your child’s swimsuit. Hand wash with gentle detergent, avoid harsh chemicals or bleach, and always air dry. Never put baby swimwear in the dryer, as heat damages elastic fibers and protective coatings.

Complementing swimwear with sun safety accessories

Even the best swimwear leaves some skin exposed. Round out your sun protection strategy with these accessories:

• Kids' wide-brim sun hats protect your baby's face, ears, and neck from direct sunlight. Look for hats with adjustable chin straps that stay secure during active play.
• UV-protective sunglasses shield delicate eyes from harsh glare and UV damage with infant sunglasses featuring flexible, unbreakable frames and straps.
• Choose reusable swim diapers for economy and sustainability, or disposable versions for convenience. Never use regular diapers in the pool; they absorb water and are unhygienic.

Sun protection tips emphasize that swimwear is one component of a comprehensive strategy. Seek shade during peak sun hours (10 AM to 4 PM), take regular breaks from direct sunlight, and watch for signs of overheating or sunburn.

😎 Check today’s UV index.

Additional tips for one-year-old swimmers

Beyond choosing the right swimwear, these practical tips help keep your baby safe and comfortable:

• Start swim lessons early: Water safety education can begin as early as six months. Teaching your child water skills is the best way to protect them against accidental drowning. Learn what to bring to your child’s first swim lesson.
• Use family matching swimwear: It creates adorable photo opportunities and strengthens family bonds. SwimZip's coordinated collections help you spot family members quickly in crowded areas when everyone wears the same distinctive pattern.
• Layer for temperature control: A long-sleeve rash guard can cover a one-piece or a sunsuit for additional warmth.
• Choose fun patterns: Lemon prints, tropical prints, and gingham designs coordinate easily with other pieces for mix-and-match versatility. These patterns pair with high-visibility accessories so your child can rock their style and stay seen.
• Maintain constant supervision: Drowning happens quickly and silently. Assign a designated water watcher who maintains constant visual contact. Learn how to keep your kid safe at the pool.

Ready to dress your one-year-old?

SwimZip's sun-protective swimwear combines UPF 50+ protection, full-length zippers, and high-visibility colors in designs made for one-year-olds. Every suit carries the Skin Cancer Foundation Seal of Recommendation for guaranteed UV protection. Find swimwear that keeps your baby safe, comfortable, and easy to change.

👶 Shop our baby swimwear collection.

Kids’ swimwear FAQ

Is UPF 50+ really necessary for a one-year-old?

Babies have significantly thinner, more vulnerable skin than adults, and their melanin production is minimal. A single severe sunburn in childhood can double the lifetime risk of melanoma, the deadliest form of skin cancer. UPF 50+ fabric blocks 98% of harmful rays, providing protection far beyond regular swimwear or sunscreen.

Can a one-year-old go in a chlorine pool?

One-year-olds can safely swim in chlorinated pools. The chlorine levels in residential and public pools are regulated to be safe for young children

Rinse your baby with fresh water immediately after swimming to remove chlorine residue from skin and swimwear. Some babies with sensitive skin may experience mild irritation, but this is uncommon with properly balanced pool chemistry.

Should a one-year-old wear a diaper in the pool?

One-year-olds must wear swim diapers in pools for hygiene and safety. Regular diapers absorb water and become extremely heavy, creating a drowning risk. Swim diapers contain solid waste while allowing your baby to move freely in water.

How should the swimsuit fit?

Swimwear should fit snugly without restricting movement. You should be able to slide two fingers under straps or waistbands, but the fabric shouldn't sag or create gaps. The suit should stay in place during active movement without riding up or pulling at the shoulders. If the suit is baggy or loose, it compromises UV protection and creates safety hazards.

What color is safest for swimwear?

Neon colors like bright orange, lime green, electric yellow, and hot pink provide maximum visibility underwater and against pool backgrounds. These high-visibility colors create strong contrast that helps you spot your child instantly in crowded or murky water. Avoid white, light blue, dark navy, or black swimwear. These colors blend with water surfaces or reduce visibility. 

How often should I wash my baby's swimsuit?

Rinse swimwear with fresh water after every use to remove chlorine, salt, or pool chemicals. Perform a wash with gentle detergent after 2–3 uses or whenever the suit seems particularly dirty or sandy. Hand washing is gentlest on the fabric and maintains UPF protection longer than machine washing. Never use bleach or harsh chemicals, which degrade protective coatings. Always air dry since heat from dryers damages elastic fibers and reduces the suit's lifespan.

When should I replace my one-year-old's swimsuit?

Replace swimwear when you notice stretched-out elastic, faded colors, thinning fabric, or loose seams. Most quality suits last one full season (3–4 months of regular use) before showing wear. If the suit no longer fits snugly or has lost its stretch recovery, it's time for a new one. Additionally, replace suits when your baby outgrows the size.

Further reading

Rash guard vs swimsuit for baby

What is the best color swimsuit to wear in the pool?

What is the best color swimsuit to wear in the ocean?

Does UPF wash out of clothing?

Kids’ sun safety tips