How to Put On a Baby One-Piece Swimsuit Without the Fuss

By Mix n' Match Swimsuits & Swimwear | Kortni Jeane | Published: 2026-10-31

Category: Tips & Care

A calm, step-by-step routine for getting a baby into a Simply One-Piece swimsuit, with checkpoints for straps, lining, and post-swim care.

Quick answer

Lay the suit flat, open the leg and neck openings wide with both hands, and guide your baby's legs in one at a time while she sits or lies on a towel. Then ease the straps over the shoulders and check that the lining sits smooth before you pick her up.

Why a one-piece can feel harder than it looks

A one-piece has no separate top and bottom to adjust, so all the stretch happens at the leg openings and straps. That is good news for coverage, but it means you need to open the suit wider than you think before your baby's feet go in.

The Baby Simply One-Piece has thin shoulder straps that are not adjustable and a straight cut across the front. Because the straps do not loosen, the neck opening is the tightest part to pass over the head or shoulders, so plan that move before you start.

When to dress her and when to wait

Put the suit on at home or at the pool only after sunscreen, a diaper change, and a feed are done. Dressing a baby who is hungry or sleepy turns a 30-second job into a wrestling match.

If the suit feels tight at the legs but loose at the shoulders, check the size before you force it. The Baby Simply One-Piece is listed as true to size, so a suit that needs tugging at the leg piping is usually a signal to size up rather than pull harder.

Step-by-step: dressing your baby in a Simply One-Piece

Set up a flat, dry surface: Lay a towel on the floor or changing table and place the suit flat with the front facing up. Open the leg openings and the neck opening with both hands so the fabric is already stretched. Checkpoint: the suit should look wider than your baby's hips before you lift her.
Seat her on the suit: Sit your baby on the back panel of the suit, facing you, with the leg openings gathered in each hand. Guide one foot through the nearest leg opening, then the other, keeping the piping flat against her skin. Common mistake: pulling both legs through at once, which bunches the lining and twists the leg piping.
Bring the front up in one motion: Hold the front panel at the waist and pull it up over her belly in a single smooth movement, rather than inching it up. This keeps the lining from folding over itself. Checkpoint: run a finger along each leg opening to confirm the piping lies flat and no lining is trapped.
Ease the straps over the shoulders: Because the straps are not adjustable, widen the neck opening with both hands and guide it over the back of her head first, then settle each thin strap onto a shoulder. Let her arms stay relaxed rather than threading them through. Common mistake: tugging a strap upward from the front, which strains the seam and leaves the suit twisted.
Smooth and check the fit: Run your hands from the shoulders down to the leg openings, flattening the front panel and the straight cut across the chest. Check that the straps sit on the shoulders without digging in and that the leg openings are not riding up. If the straps leave red marks or the legs creep up within a minute, try the next size rather than adjusting the suit.
Rinse and dry after swimming: Rinse the suit in cool water after each swim, gently squeeze out the water without wringing, and lay it flat to dry out of direct sun. Wash it with a mild detergent when needed and skip fabric softener. Checkpoint: store the suit fully dry and unfolded so the thin straps keep their shape for the next wear.

Product facts that help

Baby Simply One-Piece: Completely lined one-piece with thin, non-adjustable shoulder straps and piping around the legs. The full lining adds a layer to smooth down as you dress her, and the fixed straps mean the neck opening will not stretch to help you.
Baby Simply One-Piece