ThredUp LogoThredUp
Beta

Find girls' one pieces at up to 90% off estimated retail prices when you shop at thredUP. Get pre-loved items from your favorite girls' brands, like Baby Gap and Carter's.

958 items
Sort by:
    The Edit. Forever Classic, Get perfectly polished in trousers, blazers, and more. Shop The Edit
    Speedo One Piece Swimsuit (view 2)Speedo One Piece Swimsuit (view 1)
    View Product: Speedo One Piece Swimsuit

    Speedo

    One Piece Swimsuit
    Size X-Small kids
    $11.99 $6.59 45% off with code GOBIG
    50% off estimated retail
    H&M One Piece Swimsuit (view 2)H&M One Piece Swimsuit (view 1)
    View Product: H&M One Piece Swimsuit

    H&M

    One Piece Swimsuit
    Size 3-6 mo
    $8.99 $4.94 45% off with code GOBIG
    38% off estimated retail
    Unbranded One Piece Swimsuit (view 2)Unbranded One Piece Swimsuit (view 1)
    View Product: Unbranded One Piece Swimsuit

    Unbranded

    One Piece Swimsuit
    Size Small tots
    $12.99 $7.14 45% off with code GOBIG
    45% off estimated retail
    Capezio One Piece Swimsuit (view 2)Capezio One Piece Swimsuit (view 1)
    View Product: Capezio One Piece Swimsuit

    Capezio

    One Piece Swimsuit
    Size Small kids
    $9.99 $5.49 45% off with code GOBIG
    55% off estimated retail
    Next One Piece Swimsuit (view 2)Next One Piece Swimsuit (view 1)
    View Product: Next One Piece Swimsuit

    Next

    One Piece Swimsuit
    Size 90 cm
    $7.99 $4.39 45% off with code GOBIG
    56% off estimated retail
    Coolibar One Piece Swimsuit (view 2)Coolibar One Piece Swimsuit (view 1)
    View Product: Coolibar One Piece Swimsuit

    Coolibar

    One Piece Swimsuit
    Size Large youth
    Baby Gap One Piece Swimsuit (view 2)Baby Gap One Piece Swimsuit (view 1)
    View Product: Baby Gap One Piece Swimsuit

    Baby Gap

    One Piece Swimsuit
    Size 18-24 mo
    $9.99 $5.49 45% off with code GOBIG
    63% off estimated retail
    H&M One Piece Swimsuit (view 2)H&M One Piece Swimsuit (view 1)
    View Product: H&M One Piece Swimsuit

    H&M

    One Piece Swimsuit
    Size 2
    $6.99 $3.84 45% off with code GOBIG
    46% off estimated retail
    Cat & Jack One Piece Swimsuit (view 2)Cat & Jack One Piece Swimsuit (view 1)
    View Product: Cat & Jack One Piece Swimsuit

    Cat & Jack

    One Piece Swimsuit
    Size Large youth
    $9.99 $5.49 45% off with code GOBIG
    41% off estimated retail
    Zara One Piece Swimsuit (view 2)Zara One Piece Swimsuit (view 1)
    View Product: Zara One Piece Swimsuit

    Zara

    One Piece Swimsuit
    Size 12-24 mo
    $9.99 $5.49 45% off with code GOBIG
    54% off estimated retail
    Sporti One Piece Swimsuit (view 2)Sporti One Piece Swimsuit (view 1)
    View Product: Sporti One Piece Swimsuit

    Sporti

    One Piece Swimsuit
    Size X-Small youth
    $11.99 $6.59 45% off with code GOBIG
    25% off estimated retail
    Dolfin One Piece Swimsuit (view 2)Dolfin One Piece Swimsuit (view 1)
    View Product: Dolfin One Piece Swimsuit

    Dolfin

    One Piece Swimsuit
    Size X-Large tots