Slytherin is one of the kindest houses to dress as, because the rules are short: green and silver for colour, a serpent for the emblem, and a black robe over almost anything. That leaves room for school uniforms, character costumes, Quidditch kit, velvet formalwear and a few historical takes. Most of what follows comes together from closet basics, a thrift-store run and one or two small sewing jobs, and I'll point out which pieces are worth making yourself. Each idea covers clothing, hair, makeup, shoes and props, so you can plan for Halloween, a school spirit day or a themed party without a pile of mismatched extras.
Turning a Thrifted Graduation Gown Into a House Robe
Nearly every costume on this list hangs on a black robe, and you don't need a pattern to get one. A secondhand graduation gown is already the right shape: long, full and open at the front. It just needs the house colour added where people will see it.
- Try the gown on over the layers you'll wear underneath and mark the hem an inch or two above the floor, so it won't catch on stairs.
- Cut a band of emerald fabric about 10 cm wide and as long as the front opening plus the neckline. Satin or polyester lining fabric looks right; cotton is easier to sew.
- Fold the band in half lengthwise, press it, and stitch it along the inside of the front edges so a strip of green shows when the robe hangs open.
- Line the inside of the sleeve hems the same way, since the green flashes every time you lift your wand hand.
- Remove or unpick the graduation zip if it bothers you, then add a hook-and-eye or a small clasp at the collarbone so the robe stays on your shoulders.
Graduation gowns are usually polyester, so press them on a low heat with a cloth between iron and fabric; a hot iron leaves shiny marks that never come out. A felt or embroidered crest stitched on the left chest is the last step, and it can be tacked on with a few stitches if you want to reuse the gown for something else later.
1. Classic Slytherin Student Costume
This is the uniform everyone pictures, and the one I'd make first because every other version borrows from it. A crisp white button-down, black straight-leg trousers or a knee-length pleated skirt, a grey V-neck jumper, the green-and-silver striped tie and a long black robe lined in emerald. If you only sew one thing, sew that lining: a black robe reads as generic wizard until the green shows at the front edge and the sleeve. Black loafers, Oxfords or lace-ups keep it practical. Hair neat, waves, a low ponytail or a clean side part all suit. Keep makeup to defined brows, light foundation and a soft green liner. A wand, an old hardback and a small serpent pin finish it, and the same pieces scale down for children or layer up with thermals for a cold night.
2. Slytherin Skirt Uniform Costume
A pleated skirt gives the uniform a little more personality. Pair a black or charcoal plaid skirt with a fitted white shirt and a dark grey sweater vest, then add the green striped tie and black robe for colour. Thrifted school skirts are often a size or two off; I take the waist in at the side seam rather than the back, so the pleats still hang straight down the front. Opaque black tights with flat loafers, Mary Janes or ankle boots keep you comfortable all day. Hair in a sleek headband, loose curls or two neat braids. A touch of silver shimmer in the inner corners and a thin emerald liner do the makeup. Carry an old-looking book, a wand or a structured satchel, and pull green knee socks over the tights if it's chilly.
3. Slytherin Trouser Uniform Costume
Tailored black trousers make the most practical version, and it works for anyone. Add a white collared shirt, a grey cardigan, the house tie and an ankle-length robe. Straight or wide legs both look right, so go with what you already own. Black Oxfords, loafers or low block-heel boots finish it. Hair slicked back, natural or with a neat side part. Matte skin, brushed brows and a little grey-green shadow are enough makeup. A leather-look book bag, a roll of parchment and a wand make good props, and a serpent brooch pinned to the cardigan adds the house mark. Robes cut to the ankle catch on stairs and car doors, so I hem mine an inch or two above the floor when the costume involves a lot of walking or sitting.
4. Slytherin Sweater Vest Costume
Skip the robe and a sweater vest carries the whole academic look on its own. Wear a dark grey or forest green V-neck vest over a white button-down, with black trousers, tailored shorts over tights, or a pleated midi skirt. Add the striped tie and a small serpent patch. I cut the patch from felt or metallic fabric and stitch it on with a few running stitches; glue lets go of knitwear the first time it stretches. Black loafers and ribbed socks keep it understated. Smooth hair, a low bun, or loose waves held back with a black headband suit it, with a thin emerald liner and a cool-toned lip. A stack of old books and a wand do for props. With no robe to manage, this is the version I suggest for a classroom, an office, a warm indoor party or a costume you put together the night before.
5. Slytherin Cardigan Costume
A dark green cardigan makes the uniform softer and more everyday. Layer it over a white shirt with a grey pleated skirt or black tailored trousers, then add the tie, a silver serpent pin and a light black robe you can take off indoors. Black tights with loafers keep it traditional; ankle-length trousers with polished lace-ups work just as well. Hair in a loose half-up, a low ponytail or a side braid. Natural foundation, rosy cheeks and green mascara are plenty. A canvas book bag with faux spell books, rolled papers and a quill gives you something to carry, and small silver rings or a metallic headband repeat the house colour. A cardigan sags under the weight of a heavy pin, so put a small felt square behind the brooch on the inside to spread the pull.
6. Slytherin Quidditch Player Costume
For the Quidditch version, wear black trousers or leggings, a dark green rugby shirt and a sweeping green-and-silver robe, with striped knee socks and sturdy lace-up boots you can be outdoors in. A felt number, a serpent patch or a strip of silver trim at the shoulders turns a plain rugby top into team kit; I stitch felt numbers on with a zigzag so they flex with the shirt. Long hair goes into a high ponytail or braid, shorter hair stays a bit tousled. Light makeup with defined brows and two small green stripes under the eyes reads as game day. Forearm guards made from brown fabric and a small broom or a green pennant finish it. Keep the broom short if you're heading into a crowd. Sporty kids and friend groups get the most out of this one.
7. Slytherin Prefect Costume
A prefect needs to look a notch sharper than the other students. Start with a white shirt, a fitted grey jumper, black trousers or a pleated skirt and a carefully knotted tie, then add a structured black robe with a silver P badge at the chest. I make the badge from craft foam or card covered in silver vinyl, with a safety pin glued to the back, which is light enough not to drag the robe down. Polished black Oxfords, clean loafers or low-heeled boots suit the role. Keep hair smooth in a bun, ponytail or a sharp side part. Matte skin, a little contour and a thin green liner keep the face controlled. A clipboard, a rolled list of school rules and a wand are fun props, and a pocket watch adds one more detail. Then stand up straight; the posture does half the work here.
8. Slytherin Head Student Costume
The head student is the most formal of the uniforms. Choose a tailored white shirt or blouse, a fitted black waistcoat, charcoal trousers or a long pleated skirt and the striped tie, with a floor-length robe and a large silver head-student badge. A waistcoat is the piece that changes the shape most, and a thrifted suit waistcoat usually needs nothing more than the back belt tightened. Sleek black boots or polished Oxfords suit the mood. Hair in a glossy low bun, smooth waves or a combed side part. Silver shadow, defined lashes and a deep berry lip keep the makeup cool. Carry a neat stack of books, an attendance ledger and a wand, and add silver cufflinks, a chain brooch or a structured satchel. It should look disciplined and a little ambitious.
9. Draco Malfoy Slytherin Costume
Draco is all about the hair and the pressing. A fan-made version needs a white shirt, black trousers, a grey V-neck jumper, the house tie and a long robe, and every piece should be ironed flat, because his whole character is looking immaculate. Polished black shoes finish the uniform. A short platinum wig or light hair combed into a smooth side part gives you the face. Shop platinum wigs often come out of the bag far too shiny; a light dusting of dry shampoo knocks the shine down so it looks like hair. Pale matte foundation, softly defined cheekbones and cool grey shading round the eyes are enough. Keep the props to a wand and one old book, with a silver serpent pin on the jumper. Play it with a raised eyebrow and a bored stare rather than big theatrics.
10. Pansy Parkinson Slytherin Costume
Pansy Parkinson works as a fashionable take on the standard uniform. Combine a fitted white blouse, a cropped grey jumper, a black pleated skirt and the striped tie, with opaque tights, glossy Mary Janes and a fitted black robe. A short dark bob wig gives the hairstyle; dark natural hair can be straightened and tucked behind the ears instead. If you crop a jumper yourself, fold the hem up and stitch it as a casing rather than just cutting it, because cut knit unravels within an evening. Sculpted brows, grey-green shadow, mascara and a muted rose lip suit her. A small structured handbag, a wand and a slim notebook are her props, and silver hair clips or a tiny serpent brooch finish it. Keep everything coordinated rather than dramatic, and it stays comfortable and family-friendly.
11. Severus Snape Slytherin Costume
Snape skips the student uniform for long black layers. Wear a high-neck black shirt or a buttoned tunic with straight black trousers and a long, flowing black coat, plus simple flat black boots. His coat is known for its long row of small buttons; I fake them with a strip of black ribbon and evenly spaced shank buttons sewn on top, which is quicker than buttonholes and you open the coat with hidden snaps. A shoulder-length straight black wig with a centre part is the hair. Pale foundation, a soft hollow under the cheekbones, straight dark brows and a little grey under the eyes do the face, nothing gruesome. Carry a small book of handwritten potion notes, a few labelled empty bottles and a slender wand. It's plain in colour but strong in outline, which is why the coat length matters most.
12. Bellatrix Lestrange Slytherin Costume
Bellatrix can look wild without anything graphic. Begin with a long black dress with layered fabric, bell sleeves or an uneven but modest hem, then add a fitted black waistcoat or a lace-up corset belt over it. Opaque tights and sturdy black ankle boots go underneath. The wig is the costume: a long, dark, voluminous curly wig with a few strands loose round the face. Curly synthetic wigs tangle badly if you brush them dry, so I finger-separate the curls with a little wig spray or diluted conditioner instead. Smoky grey eyes, strong brows and a muted plum lip suit her. Carry a wand and a small black drawstring pouch rather than anything threatening, and wear silver rings and a dark green stone pendant for the house. Movement, tangled curls and an intense stare carry it.
13. Narcissa Malfoy Slytherin Costume
Narcissa is the elegant one, so she suits anyone who'd rather wear formalwear than a uniform. A floor-length black dress, or a fitted black top with a flowing maxi skirt, sits under a structured dark green coat, a velvet capelet or a black jacket with silver detail. Pointed flats or low ankle boots keep you comfortable. The two-tone hair is her signature: a long blonde wig with one bold black section, in smooth waves or a half-up style. If you can't find one, I'd sew a dark weft into the underside of a blonde wig rather than paint it, because paint on synthetic fibre stiffens and flakes. Luminous skin, soft contour, silver-grey shadow and a mauve lip finish the face. A small black clutch, a slim wand, a silver pendant, a green ring and elegant gloves are all she needs.
14. Lucius Malfoy Slytherin Costume
Lucius mixes historical tailoring with cold silver details. Wear black trousers, a high-collared white or black shirt, a brocade waistcoat and a long black coat, with knee-high black boots or polished dress shoes. A long, sleek, straight platinum wig with the front tucked behind the shoulders gives his look. His walking stick is the prop people know. I make mine from a length of dowel painted black with a silver-painted foam or resin topper glued on, which is light enough to carry all night and won't cause problems at the door. A pair of black gloves, pale even foundation, defined cheekbones and soft grey shadow finish it, with a green stone brooch or a serpent clasp tying it to the house. Keep the expression calm. It's a good adult costume for anyone who enjoys detailed aristocratic clothing.
15. Tom Riddle Slytherin Student Costume
Young Tom Riddle should look like a perfectly kept vintage uniform. A white button-down, a charcoal sweater vest, a narrow striped tie and high-waisted black trousers go under a long school robe, with polished black lace-ups. A narrow tie is a quick sewing job: fold a standard tie lengthwise and stitch a new back seam a centimetre or two in, then trim. Dark hair with a clean side part and a little styling cream gives the 1940s finish. Matte foundation, straight brows and light grey contour under the cheekbones keep the makeup quiet. Carry a worn diary-style notebook, a fountain pen and a wand, with only a silver ring or a small serpent pin for jewellery. Everything neat and controlled, plus a thoughtful, slightly too still expression, is what separates him from any other Slytherin student.
16. Salazar Slytherin Founder Costume
The house founder becomes a regal medieval costume in layered green and silver. Start with a long dark green tunic or a modest floor-length dress, then add a silver-trimmed black robe, a wide belt and a textured shoulder cape. Tall black boots or simple flats go under the hem. Silver trim on a robe is easiest from a roll of metallic braid stitched along the front edge; it frays less than metallic fabric cut into strips. Long dark or grey hair, natural or from a softly waved wig, suits him. Defined brows, cool contour and deep green shadow blended lightly round the eyes do the face. Carry an old book, rolled school plans and a carved-looking wand, and add a serpent brooch, an emerald-coloured ring or a silver circlet. Use fabric serpents, never real animals. Dignified and ancient is the goal, not sinister.
17. Scorpius Malfoy Slytherin Costume
Scorpius is the relaxed, slightly rumpled student. Wear a white shirt with the collar a little loose, a grey sweater vest, black trousers, the striped tie and a light black robe, with clean black sneakers, lace-ups or comfortable Oxfords. A short, tousled platinum wig is his strongest detail; I tease the crown with a wide-tooth comb so it looks lived-in rather than salon-fresh. Natural makeup with lightly defined brows and a little cool shadow suits him. Carry several books, rolled parchment and a modest wand. Add a green scarf for outdoors or a silver serpent pin for indoor events. Studious and friendly is the mood. Because the robe can be light and the shoes are sneakers, this is one of the most comfortable picks for teens, children or a long day on your feet.
18. Astoria Greengrass Slytherin Costume
Astoria Greengrass mixes the schoolwear with softer green accents. Pair a white blouse with a charcoal pleated midi skirt, a slim green tie, a fitted grey cardigan and a black robe, plus opaque tights and low-heeled Mary Janes or polished ankle boots. Medium or long hair suits smooth waves, a braided half-up or a neat low bun. Keep the makeup gentle: fresh skin, muted green shadow, light mascara and a rose lip. A green-covered book, a silver clutch and a small wand are her props, and an emerald ribbon tied at the collar or a vintage serpent brooch adds the house. A midi pleated skirt looks best when the pleats are pressed sharp; I tack them flat at the hip with a few hand stitches on the inside so they don't spring open. It's a fan-made look that suits school and family events.
19. Merlin Slytherin Wizard Costume
Imagine Merlin as a distinguished Slytherin wizard in layered emerald and silver. Start with black trousers and a dark green tunic, then add a long robe edged in silver or embroidered with stars, a braided belt at the waist and soft black boots. A long silver-grey wig and matching beard should be brushed and neat, not oversized. Beards on elastic slide down your chin as you talk, so I add a second strip of elastic over the top of the head, hidden under the wig. Soft brow shading and a few fine lines round the eyes are enough ageing. Carry a tall staff made from foam or cardboard, an old book and a small green pouch, and add a silver circlet or serpent clasp. It's a wise, magical alternative to the student uniform.
20. Dark Academia Slytherin Costume
Dark academia is the Slytherin costume you'll keep wearing in November. Layer a white or cream button-down under a forest green sweater vest and a brown or charcoal plaid blazer, with high-waisted black trousers or a calf-length pleated skirt, dark socks and leather-look loafers. Throw a black academic robe over the top when you want it to read as a costume. Hair in loose waves, a low bun or a tidy side part. Brown-green shadow, natural skin and a muted berry lip suit it. Carry vintage books, a leather-look satchel, rolled papers and a wand, and add round glasses, silver rings and a serpent brooch. I pin the brooch rather than sewing anything permanent onto the blazer, so the whole outfit goes back into your wardrobe afterward.
21. Gothic Slytherin Formal Costume
For gothic formalwear, start from black with emerald velvet accents. One version is a high-neck maxi dress with a fitted green waistcoat, opaque tights and pointed ankle boots; another is black trousers, a ruffled shirt, a velvet blazer and polished boots. Either takes a silver-trimmed cape. Velvet crushes where you sit, so I hang the jacket or dress in a steamy bathroom an hour before leaving rather than ironing it, which flattens the pile. Glossy waves, a braided updo or smooth combed-back hair all work. Smoky grey eyes, a precise green liner, pale luminous skin and a deep berry lip finish the face. Carry a small book, a silver-handled cane or a wand, and add serpent jewellery and an emerald brooch. It's dramatic enough for a formal party and still tasteful.
22. Green Velvet Slytherin Witch Costume
Emerald velvet turns a plain witch into a Slytherin one. Wear a long green velvet dress with a fitted waist and flowing sleeves, then add a black cape lined with silver fabric and a wide-brimmed black hat trimmed with green ribbon and a small serpent brooch. Opaque tights and black ankle boots go underneath. A cape lining in slippery silver fabric slides off your shoulders, so I add a small hook-and-eye at the neck and a strip of grip tape under the collar. Long waves, a side braid or a low twisted bun under the hat suit it. Silver-green shadow, defined lashes and a soft plum lip finish the face. Carry a small broom, a green spell book and a wand. Leave out anything too spooky and it stays family-friendly, and it gives you the house colours without wearing a uniform or playing a particular character.
23. Slytherin Princess Costume
A Slytherin princess puts a fairytale shape into the house colours. Choose a modest floor-length green gown with a fitted bodice and full skirt, then add a silver belt, a black velvet cape and a delicate serpent-inspired tiara. Silver flats or low black shoes under the dress keep walking easy. A braided crown, polished curls or a long half-up style all suit it. Green shimmer on the lids, soft pink cheeks and a berry lip keep the makeup luminous. Carry a silver wand and a small green book rather than anything oversized, with long gloves and an emerald pendant. For a child, I'd shorten the gown to the ankle and skip the gloves; little ones trip on long hems and peel off gloves within ten minutes. Teens and adults can keep the full length.
24. Renaissance Slytherin Costume
A Renaissance version is a fun historical twist that still shows green and silver clearly. Wear a white puff-sleeve blouse under an emerald bodice or structured vest, then a long black or green skirt, or fitted black trousers with knee-high boots. A dark cape fastened with a silver serpent clasp goes over the top. Loose curls with small side braids, or a shoulder-length wavy wig, suit it. Natural skin, softly defined eyes and a muted berry lip are enough. Carry a leather-look book pouch, rolled parchment and a decorative wand. This is where a little sewing pays off: silver trim, ribbon or simple embroidery added to inexpensive thrifted pieces makes them look handmade on purpose, and I keep stitches loose enough to unpick so the blouse can be worn again.
25. Victorian Slytherin Costume
High collars and tailored layers give the Victorian version a serious, scholarly mood. Wear a white high-neck blouse with a black waistcoat and a long green skirt, or a dark frock coat with black trousers, plus a silver chain brooch, a narrow cape and lace-up black boots. A low twisted bun, structured waves or a neat side part suits it, with matte skin, softly shaded eyes and a rose-brown lip. Carry a small hardback book, a pocket watch, gloves and a wand. A dark green ribbon tied at the collar replaces the striped school tie and keeps the colours. A long skirt that's a little too short looks wrong for the period, so I let the hem down or add a deep band of matching fabric at the bottom. It suits adults who enjoy vintage clothing.
26. Winter Slytherin Student Costume
For a cold night, the costume has to be built from real warm layers, not just a robe. Wear a white collared shirt under a chunky grey jumper and black wool trousers or a thick pleated skirt, with green-and-silver striped socks and insulated black boots. The robe has to fit over all that knitwear, so I size up or cut the robe with extra width across the back. A dark green scarf and silver gloves help outdoors, and hair can go under a black knit hat or into a low braid. Keep makeup simple: moisturiser, rosy cheeks and a waterproof green liner. A covered travel mug, a closed book and a short wand are practical props, and a serpent pin on the scarf keeps the house visible when everything else is buttoned up. It's the version for parades, outdoor festivals and chilly trick-or-treating.
27. Summer Slytherin Student Costume
Warm weather needs the opposite: the fewest layers that still read as Slytherin. Choose a short-sleeve white button-down with black tailored shorts or a breathable pleated skirt, a loosely knotted house tie, and an unlined robe in thin fabric. Ankle socks with loafers, Mary Janes or black sneakers finish it. A high ponytail, braid, bun or short slicked-back hair keeps you cool, with light foundation, a waterproof green liner and tinted lip balm. A small crossbody bag, a mini notebook and a light wand are enough to carry. I'd stitch a serpent patch onto the shirt itself, because the robe will come off at some point and the costume still needs to say which house you're in.
28. Last-Minute Slytherin Costume
Short on time, this version comes almost entirely from your closet. Start with a white button-down and any black trousers, skirt or tailored shorts, and layer a grey jumper or cardigan on top. The tie is the one thing you'll probably need to make: a strip of green ribbon or felt, or an inexpensive green scarf folded narrow, does it, and strips of silver tape across it give the stripes. A black graduation gown, a long cardigan or a light coat stands in for the robe, with black shoes and plain socks. Hair neat, green liner or silver shadow, and a serpent drawn on card and pinned to the chest. A painted chopstick makes a light wand next to an old book. It's cheap, comfortable and realistic to pull off on the day.
29. Slytherin Couple Costume
A couple can show two sides of the house. One wears the classic student uniform: white shirt, green tie, grey jumper, black trousers, robe and Oxfords. The other wears the green velvet witch look: long dress, silver belt, black cape, pointed hat and ankle boots. Keep both hairstyles polished, a side part for the student and waves or a braid for the witch, and tie the faces together with the same emerald liner and cool silver highlight. Give each person a different prop, a book and wand for one, a small broom and green pouch for the other. I'd match the exact green of the tie to the velvet dress before buying either; two greens that are slightly off look much worse side by side than two that are clearly different.
30. Slytherin Group Costume
A group costume works best when each person plays a different role in the same house. Mix a classic student, a prefect, a Quidditch player, a dark academia scholar, a green velvet witch and a formal alumnus. Repeat green ties, silver serpent pins and black robes across everyone, and vary what's underneath: pleated skirts, tailored trousers, rugby tops, velvet dresses, waistcoats, long coats. Practical black shoes, loafers to boots, keep the group able to walk together. Hair can go from neat buns and braids to platinum wigs and side parts, with subtle green liner or silver shadow on everyone. Give each person a safe prop: a book, a pennant, a short broom, a clipboard or a wand. When I'm making ties for a group, I cut them all from the same ribbon roll in one session so the stripes match exactly.
Sewing a Striped Tie That Lies Flat
The striped tie is the second piece that gives the house away, and shop costume ties are often thin and shiny. Making one takes about an hour. I start from a plain dark green tie bought secondhand, because the shape and interlining are already right, and add the silver stripes on top.
- Cut silver or grey grosgrain ribbon into pieces a little wider than the tie, and lay them on the diagonal, every stripe at exactly the same angle.
- Space the stripes evenly; a strip of card cut to the gap width keeps them consistent all the way down.
- Fuse each stripe with a narrow strip of iron-on bonding web, then fold the ends under at the back of the tie and add a couple of hand stitches.
- Skip hot glue. It shows through as lumps, stiffens the tie so it won't knot, and lets go when the tie is pulled tight.
For a child or a quick costume, a clip-on is kinder: cut the finished tie short, fold the top into a knot shape and stitch it to a metal tie clip or a loop of elastic. It also stops anyone being grabbed by the tie in a playground.
Platinum and Raven Wigs Without the Plastic Shine
Several of these characters depend on the hair, and cheap wigs at either end of the colour range give themselves away first. Platinum and jet black synthetics both have a glassy shine under room lights and flash. A light mist of dry shampoo or a dusting of translucent powder, worked through with your fingers, takes most of it down.
Long straight wigs, for the Lucius and Snape looks, tangle at the nape where they rub a collar; a few drops of wig spray and a wide-tooth comb from the ends upward fix that, and a wig cap keeps your own hair from pushing through. Keep any synthetic wig away from hot styling tools unless the label says it's heat-safe, because it will frizz or melt. Store it on a stand or a tall jar between wears, not folded in a bag, so it's ready for the next party.
Green Tie, Black Robe, Then Make It Yours
Green and silver can carry far more than one school uniform. You can stay traditional with a robe, a tie and polished shoes, or go personal with historical clothing, velvet formalwear, sports kit or a character's signature hair. Whichever you choose, repeat emerald, silver, black and charcoal from head to toe, and let hair, makeup, shoes and one or two props finish the job. If I had an afternoon and a sewing machine, I'd spend it on the robe lining and the tie, since those two pieces make even a closet-built version look intentional. After that, choose layers and shoes for the weather and the age of whoever's wearing it, so the costume lasts the whole evening.
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