Cozy Knitted Baby Onesie Pattern (6–9 Months) — Easy DK Romper with Ruffled Legs

A sweet, cozy knitted baby onesie that’s perfect for snuggles and photos. This pattern is worked with two strands of DK yarn held together for a soft, warm fabric and is sized for a 6–9 month baby. Below you’ll find materials, gauge, abbreviations, and the full step-by-step pattern to knit the body, front, suspenders, and ruffled legs.

Materials and tools:

• Circular knitting needles 3.5 mm – 80 cm and double-pointed needles (dpn) same size (US 4)
• Crochet hook 3.5 mm
• Rainbow Baby DK – 100% acrylic. Color of your choice. In total 1.5 skeins.

Size: Baby: 6–9 months

Gauge: 18 sts = 4 inches in stockinette (worked with two strands held together)

Note: Knit with two strands of yarn at once.

Abbreviations:

• k – knit
• p – purl
• st(s) – stitch(es)
• yo – yarn over
• pm – place marker
• sel s – selvage stitch: always slip the first stitch purlwise, work to the last stitch, purl the last stitch
• M1R – make one right increase: pick up bar bringing left hand needle from the back to the front, then knit the bar through the front loop
• M1L – make one left increase: pick up bar bringing left hand needle from the front to the back, then knit the bar through the back loop
• p2tog – purl two together
• Bind off – slip first stitch, k1, pass stitch over, *k1 pass stitch over, * repeat till the end

Knit baby onesie pattern

Knit the body of the onesie

To get started with the baby romper we are going to use a provisional cast on method. Using a smooth piece of scrap yarn (preferably in a different color so that you can identify it easily later), crochet chain 22–23. Take the knitting needles and pick up 16 stitches through the “bumps” on the back of the chain. Count your stitches when you are done.

Row 1 (RS): sel s, knit all stitches, sel s. Place a stitch marker on the right side to identify the RS later.

Rows 2–11: repeat Row 1.

Row 12: sel s, k1, M1R, knit all stitches until the last 2, M1L, k1, sel s. (18 stitches)

Row 13 (WS): sel s, knit all stitches, sel s.

Row 14 (RS): sel s, k1, M1R, knit all stitches until the last 2, M1L, k1, sel s. (20 stitches)

Row 15 (WS): sel s, knit all stitches, sel s.

Repeat Rows 14–15, increasing from the right and from the left side, until you have 40 stitches. At the very end do not forget to knit a wrong side row. Cut the yarn leaving a 10–15 cm tail.

Unravel the provisional cast-on and get live stitches back onto the needle (16 stitches).

Row 1 (RS): sel s, knit all stitches, sel s.

Rows 2–10: repeat Row 1.

Row 11 (RS): sel s, k1, M1R, knit all stitches until the last 2, M1L, k1, sel s. (18 stitches)

Row 12 (WS): sel s, knit all stitches, sel s.

Repeat Rows 11–12, increasing from the right and from the left side, until you have 26 stitches. At the very end do not forget to knit a wrong side row. Cut the yarn leaving a 10–15 cm tail.

Now place the piece so the side with 40 sts is down and the side with 26 sts is up.

Round 1: Cast on 7 sts to the right-hand needle, k26, cast on 7 sts, k40, pm. From this point we will work in the round. To get a garter stitch texture we will knit one round and then purl the next.

Round 2: purl all stitches around (80 stitches)

Round 3: knit all stitches around (80 stitches)

Round 4: purl all stitches around (80 stitches)

Repeat Rounds 3–4 until the length above the 7 sts you cast on reaches 7.5–8 cm.

Now we will knit a belt with eyelets where an i-cord can be threaded later.

Round 1–5: [k1, p1] – repeat to end.

Round 6: [k2tog, yo, k1, p1] – repeat to end.

Round 7: [k1, purl yo through the back loop, k1, p1] – repeat to end.

Round 8–10: [k1, p1] – repeat to end.

Knit the front piece

From this point we will knit flat in rows.

Row 1 (RS): k1, p1, k1, k33, sel s, turn.

Row 2 (WS): sel s, k32, sel s, turn. (do not knit first 3 sts)

Row 3 (RS): sel s, k32, sel s, turn.

Row 4 (WS): sel s, k32, sel s, turn.

Repeat Rows 3 and 4 ten more times.

Row 25 (RS): sel s, k32, sel s, turn.

On the wrong side we will bind off the central stitches and then proceed with suspenders.

Row 26 (WS): sel s, k8, bind off next 16 stitches, k8, sel s.

Knit the suspenders

Change to dpn.

Row 1: sel s, k7, sel s, turn.

Row 2: sel s, k7, sel s, turn.

Repeat Row 2 until suspender reaches 19 cm.

Next row (buttonhole row): sel s, k2, p2tog, yo, k3, sel s.

Next 5 rows: sel s, k7, sel s, turn.

Bind off all stitches.

Repeat for the second suspender.

Knitting the ruffles of the onesie

Now pick up stitches around the leg openings.

Round 1: *Pick up 1 st, yo – repeat to the end of the round.

Round 2: *p2, yo – repeat to the end of the round. Purl the yo of the previous round through the back loop to reduce holes.

Round 3: knit all stitches. Knit the yo of the previous round through the back loop to reduce holes.

Round 4: knit all stitches.

Round 5: purl all stitches.

Round 6: knit all stitches.

Round 7: purl all stitches.

Round 8: knit all stitches.

Round 9: purl all stitches.

Repeat for the second leg.

If you prefer, you can leave the suspenders without ruffles. The pattern author prefers a bodysuit with lots of ruffles.

Pick up stitches on the right side. The ruffle portion can be shorter or longer depending on your preference. For the right suspender pick up stitches starting from the top and for the left ruffle pick up stitches starting from the first stitch of the front piece.

Row 1: * pick up 1 st, yo – repeat to the end of the round. Do not make yo at the end.

Row 2: sel s, k1, yo, *k2, yo – repeat to the end of the round, sel s.

Rows 3–9: sel s, knit all stitches, sel s.

Finishing: weave in tails, block gently if desired, and thread an i-cord or ribbon through the belt eyelets to finish. Add buttons or fastenings to the suspenders as you like (not specified in the original pattern).