American Girl Knit Pattern
One Piece Bathing Suit

Here an American Girl Knit pattern for a stylish one piece bathing suit. I used a worsted weight, soft, acrylic yarn because it is machine washable. The white looks stunning on this 18 inch doll.

This bathing suit is knit in one piece, with a seam down the back and along the back just above the crotch.

You will need to know the following abbreviations:

YO Yarn Over (Wrap the yarn around the right needle from back to front)

sl 1 Slip the next stitch from the left needle to the right needle

K2tog Knit 2 together (put the right needle through 2 stitches from the left needle and K them together)

PSSO Pass the slipped stitch over the last stitch (in this pattern, the K2tog stitch)


Gauge: 9 sts = 2 inches using worsted weight yarn and Size 3 Needles.

Cast on 32 stitches.

Row 1: K2, (YO, K5, sl 1, K2tog, PSSO, K5, YO, K2)*, repeat * once.

Row 2: Purl (32 sts)

Rows 3-10: Repeat Rows 1 and 2 four times.

This pattern forms the top edge of the swimsuit.

Cast on 8 stitches and K across 40 stitches.

Next Row: Cast on 8 stitches and purl across the 48 stitches.

Continue with a stockinette stitch (K one row, P one row) until the piece measures 4 3/4 inches from the cast on stitches. End with a purl row.


Bind off 18 stitches and K across remaining stitches.

Next Row: Bind off 18 stitches and P across remaining stitches (12 stitches total on needle).

First Decrease Row: K2tog, K8, K2tog. (10 sts)

Next Row: Purl.

Repeat last two rows. You will have 8 stitches on your needle.

Increase Row: Increase 1 stitch at beginning and end of this row (10 sts).

Next Row: Purl.

Repeat the last two rows three times. You should have 16 stitches.

Last Row: Purl.

Bind off 16 stitches.


This American Girl swimsuit is almost done. Follow the pattern below to complete this one piece bathing suit.

Weave the back seam. If you need help with this, I have tips embedded in a page with a pattern for a simple Barbie doll top. Scroll down the page to see how to weave a knitted seam.

Weave the crotch back edge to the back of the bathing suit, centering it across the back seam that you just completed.

This American Girl Knit bathing suit pattern gives you experience with a little bit of a lace pattern in the bodice.


The straps are formed by picking up and knitting 3 stitches, centering the top stitch over the point on each side. Knit these three stitches until each strap is 3 inches long. Bind off the 3 stitches and leave a 10 inch length of yarn. Thread a needle with this length, and sew the strap to the back edge of the bathing suit, close to the arm edge. See the picture below.

Here is another view of the strap, along the back of the bathing suit.

Want to knit these upper bands of the sandals and learn how to make your own doll sandals?

Want to see more patterns to knit for your 18 inch doll?

Return from American Girl Knit Pattern for Swimsuit to Making Doll Clothes.