I’ve always loved the idea of dressing up as a mermaid for Halloween—it’s one of those costumes that can be sweet, spooky, glam, or totally weird, depending on how you spin it. Over the years, I’ve seen people get super creative with it—like a deep sea siren with fish-scale makeup and creepy clay jaws, or a dark sea witch look made with layers of shredded fabric and organza. Someone even made a full-on Mermaid Man costume, complete with a starfish nose. What I love most is that there’s no one “right” way to do it. Whether you’re going full-on princess Ariel with a tulle tail and sparkly top or doing a gothy, distressed mermaid for a themed gala or festival, it’s such a fun DIY project. I pulled together all the best ideas I found—so if you’re planning to make your own mermaid costume this year, here’s everything you need to know.

Choose Your Mermaid Vibe

The fun part about making your own mermaid costume is that you get to decide what kind of mermaid you want to be. There’s no rulebook here. You can go full-on Ariel with a cute sparkly skirt and a seashell-inspired top, or lean into a more ethereal Renaissance festival vibe with layered tulle and a dreamy corset (someone actually made theirs with 25 yards of shiny tulle—respect).

If you’re into the darker side of things, a gothy sea witch look is always a hit—think black mesh, ripped organza, and moody makeup. I saw one that had handmade tentacles stitched from fleece and even a little seafoam ruffle. Or take it up a notch and turn yourself into a terrifying siren with SFX makeup, barnacles made from clay, and liquid latex “wounds” (yep, that’s a thing and it looked insanely cool).

And if you want to keep things light and funny? Mermaid Man from SpongeBob is weirdly iconic and people loved the DIY version with a giant starfish on the nose. Honestly, whatever your vibe is—pretty, creepy, dramatic, or just hilarious—you can totally make it work.

Here is a list of ideas:

Classic Ariel or Princess Vibes

Goth/Sea Witch Mermaid

Siren with SFX Makeup

Festival or Renaissance Mermaid

Funny Twist: Mermaid Man

DIY Mermaid Tail or Skirt Options

Let’s talk tails, because the skirt is what really makes a mermaid costume pop. There are so many fun ways to DIY it, and honestly, none of them require pro-level sewing skills.

One of my favorite versions is a fitted pencil skirt made from shiny sequin fabric with layers of tulle added around the hem to mimic fins—super simple, super cute.

You can find mermaid fish stretchy fabric on Amazon here and tulle rolls for crafts here.

Another cute option is to use scale-print spandex to make the skirt or the pants and stitch in panels of layered tulle (on the sides) for extra drama. Want to skip the stitching? I would buy these mermaid legging:

Mermaid Leggings

If you want something a little more flowy and textured, go for a layered organza look. Here is what I mean:

One costume I saw had strips of organza, mesh, and glittery fabric all ruched and spiraled together to create this shredded, sea-worn effect, it looked amazing and moved really well.

And if you’re working with whatever you have at home, don’t stress. One costume was made entirely from stash fabric, including a shoelace repurposed as a drawstring. If I had to give one tip? Don’t skip the ruching. Sewing elastic into the seams adds such a nice shape, especially if you’re working with stretchy fabric.

What to Wear on Top

Now for the top, this part’s way more flexible than you’d think. You can keep it super simple with a swimsuit-style top like this one, a bralette like this one, or a crop top you already own, and just add a little sparkle. Check out this amazing video on how to DIY an amazing top yourself.

For this you’ll need:

Glue gun

Simple bra

Sea Shells

Mermaid style ribbons/strips

Shell Shaped Beaded Chain (optional)

Boho shell charms (optional)

I saw someone draft their own top based on swimsuit patterns and used a pink shoelace as a drawstring (genius), plus velcro on the back to make it easy to get on and off. Another made a mermaid top using leftover mask straps from the pandemic—honestly love the resourcefulness haha.

You can also glue on shells, sequins, or even layer some mesh or lace over a basic bandeau. If you’re not into sewing, fabric glue or even safety pins can go a long way. Just remember—comfort is key, especially if you’re going to be in it for hours.

And if you want to save the time and just buy a top, these options are amazing!

Mermaid starfish bra

Metallic swimsuit top

Mermaid Hawaiian style bra

Purple seashell top

Accessories That Make It Magical

Here’s where you can really have fun and make the whole look feel extra special:

Mermaid crowns – use old jewelry, thrifted brooches, or leftover craft pieces. One gorgeous crown I saw was made from a repurposed brooch bouquet and looked seriously magical.

Fishnet tights for makeup – stretch them over your face or neck and dab on shimmery eyeshadow to create realistic-looking scales.

Pearls, glitter and shells – stick on flat-back pearl gems, chunky glitter, or hot glue some small shells to your top, crown, or even shoes.

Add a dinglehopper – yep, an actual fork! Tuck one into your hair or glue it onto your crown for a fun Little Mermaid reference.

Flowy shawl or seafoam wrap – something sheer and floaty adds movement and makes your whole look feel like it’s underwater.

Mermaid tights – if your skirt is short you can buy these amazing tights with glossy gold fish scale pattern from Etsy.

Check out this cute DIY hack to easily add find to your hands:

Easy Mermaid Makeup Ideas

Mermaid makeup doesn’t have to be complicated, it’s all about shimmer and a little creativity. The easiest way to get that scale effect is to stretch a pair of fishnets over your face or collarbone and lightly dab on highlighter or shimmery eyeshadow in blues, greens, and purples.

When you lift the fishnets off, boom—instant mermaid magic. I like adding a coral or peachy lip to balance out the cool tones, and if you really want to go all in, stick on a few pearls or face gems around your eyes or temples. It’s super easy, super pretty, and pulls the whole look together.

Here are a few ideas:

Siren & Sea Witch Upgrades (If You Wanna Go Dark)

If you’re in the mood for something darker, turning your mermaid costume into a siren or sea witch is such a cool twist. Start with a black or dark purple color palette—think moody, ocean-at-night vibes. You can make creepy barnacle clusters using air-dry clay or model magic and glue them onto your skin or costume. For extra eerie details, try using liquid latex to create texture or fake wounds (one person even made it look like their jaw had been torn open—wild but amazing). Layer on distressed fabrics like mesh, organza, and ripped tulle to give your tail and top that haunted, sea-worn look. It’s dramatic, creepy, and still totally wearable.

Final Thoughts

At the end of the day, the best part about a DIY mermaid costume is making it your own. Whether you’re stitching every detail from scratch or throwing something together with stuff you already have in your closet, it doesn’t have to be perfect to be magical. Add your own twist, get a little messy, and just have fun with it. That’s what makes it memorable.