Mia Thermopolis goes from awkward student to confident royal over two films, and almost every stage of that change makes a good costume. The ideas below cover her outfits from both movies, plus looks for couples, best friends and groups, from the blue plaid school uniform to royal gowns, tiaras, oversized headphones and sleepover pajamas. Each one comes with clothing, hair, makeup, shoes and a prop, because a tiara on its own rarely tells anyone which princess you mean. Most of it can come from a thrift store, your closet and a few craft supplies. Pick the moment from the films you'd most like to play, full glamour or pure early-2000s nostalgia.
Mia's Hair Tells the Makeover Story
Across both films, hair is the clearest sign of where Mia is in her story. Big, frizzy, brushed-out curls mean the awkward student, and long, sleek, center-parted hair means the princess. When I get the hair right, almost any plaid skirt or white dress falls into place around it.
For the before curls
If your hair is wavy or curly, braid it while damp the night before, sleep on it, then brush the braids out with a paddle brush in the morning. Brushing dry curls is exactly what you'd normally avoid, which is why it works here. Straight hair needs a textured brown wig. Cheap curly wigs often look too neat out of the bag, so brush them hard with a wide-tooth comb to rough up the curls.
For the after hair
Sleek hair takes a straight brown wig or a flat iron with heat protectant. If you're playing both versions in one night, don't try to straighten mid-party; wear a curly wig over your own smoothed hair and pull it off for the reveal. Thick brows tame into groomed ones in seconds with a spoolie and a little clear brow gel.
1. Mia Thermopolis School Uniform Costume
The uniform is the easiest Mia to make and the one people guess fastest. Tuck a light blue button-down into a blue plaid pleated skirt, layer a navy blazer or cardigan, and knot a navy tie loosely. Black knee-high socks go with chunky loafers, lace-up school shoes or black sneakers. Brushed-out, voluminous curls do most of the work, with wire-frame glasses and next to no makeup. A canvas messenger bag of notebooks and a handwritten diary finish her. I never iron it too neatly, because a slightly rumpled shirt is more pre-makeover Mia than a crisp one.
2. Mia Before Makeover Costume
Before the makeover, Mia is all awkward layers and untamed hair, so exaggerate both. Wear a baggy blue shirt with a long plaid skirt, an oversized navy cardigan, dark knee socks and sturdy black lace-ups. For the hair, brush out your own curls or use a brown textured wig, and thicken the brows with a soft pencil. Clear lip balm and large wire-frame glasses. Carry a worn backpack, schoolbooks and a doodled diary. A joke retainer made from craft materials can hang on a cord around your neck, but never put a craft item in your mouth. Mismatched socks and a crooked tie are the finishing touches I'd never skip.
3. Mia Makeover Reveal Costume
The makeover reveal is understated polish with a nod to what just changed. Choose a fitted navy dress, a pale blue shift or a tailored skirt suit at knee length, with sheer tights and black low pumps. Wear your hair long, sleek and center-parted. If your own hair is very curly, a straight brown wig spares it a whole night of flat-iron heat. Groomed brows, rosy blush, mascara and pink gloss, then a pearl necklace, small studs and a structured bag. Carry a pair of prop wire-frame glasses snapped in half, with no sharp edges, and wear a tiny silver crown pin to say she's just learned who she is.
4. Mia White Ball Gown Costume
The white ball gown is Mia's biggest moment. Pick a strapless or sleeveless white formal dress with a full ankle-length skirt, and add elbow-length white gloves, a silver tiara, sheer stockings and white or silver low heels. Long brown hair goes half-up with soft curled ends. Makeup should glow rather than sit heavy: pale shimmer, lashes, rosy cheeks and glossy pink lips. The black sunglasses and chunky over-ear headphones are what make it her and not a bride, so don't leave them off. A white tea-length party dress with ballet flats works if a floor-length gown isn't practical, as long as the tiara, gloves, sunglasses and headphones stay.
5. Mia Blue State Dinner Costume
The blue state dinner gown is quieter and very graceful. Look for a periwinkle, powder or lavender-blue maxi with long sleeves, a square neckline and subtle Renaissance-style details, and add a narrow satin belt, drop earrings and a small jeweled ring. Brown hair goes half-up with loose curls down the back, with cool shadow, soft blush and berry-pink lips. Long sleeves on a formal gown are often cut narrow and can bind across the upper arm, so reach forward in the fitting room before you buy. Wear silver flats or low pumps, and carry a folded place card or mini menu as the dinner joke. A tiny tiara is optional; the gown should lead.
6. Mia Rainy Ball Costume
Mia's soggy arrival makes a funny costume, and you don't have to actually get wet. Layer a white sweatshirt over a pale formal dress or a flowing white midi skirt, then add white tights and waterproof white sneakers or ankle boots. Comb clear gel through a few strands of brown hair so they look rain-soaked while the rest stays dry. Waterproof mascara, rosy cheeks and pink balm. Set a silver tiara a little off-center and carry a closed clear umbrella. Clear fabric droplets on the sweatshirt add a theatrical rain effect; I stitch them on, because fashion tape loses its grip on fuzzy sweatshirt fabric. A faux royal letter or diary finishes the story.
7. Mia Beach Party Costume
For beach Mia, think relaxed early-2000s. A colorful floral button-up goes over a simple tank, with a casual midi skirt, cropped pants or knee-length shorts. Flat sandals, a woven shoulder bag and a light cardigan for when the evening cools. Hair stays naturally wavy or a bit messy, with barely-there makeup, peach blush and tinted balm. A beach towel, a disposable-style camera and a sticker-covered diary bring the nostalgia, and a small silver crown necklace keeps the princess link without going formal. For an indoor party in October, swap the shorts for a tropical-print shirt and canvas sneakers; you'll be warmer and still read as her.
8. Mia Royal Pajama Party Costume
Royal pajama party Mia is the coziest look on the list. Choose silky blue or lavender button-up pajamas with full-length pants and a pale robe trimmed with faux feathers or satin piping. Fluffy slippers need non-slip soles, because smooth slipper soles on a polished floor are an easy way to fall. A light silver tiara sits over loose brown curls, with rosy cheeks, gloss and a touch of silver shadow. Carry a satin sleep mask, a small pillow and a diary, and hang the sunglasses or headphones around your neck. Thin satin pajamas are cold outdoors, so layer a fitted long-sleeved tee under the top if you're trick-or-treating in them.
9. Mia Red Birthday Dress Costume
Red does the work in this one. Choose a sleeveless red satin midi or a full-length gown with a clean neckline, plus matching red or metallic low heels and a small evening bag. Pin long brown curls back on one side with a jeweled barrette. Classic makeup with lashes, warm blush and a soft red lip, and choose that red in daylight next to the dress, because a lip slightly off the fabric color looks wrong in every photo. A silver tiara, delicate earrings and cream opera gloves add royal drama. A wrapped present or a light faux cake box with ribbon is the prop. It looks dressy before you add a single princess accessory.
10. Mia Pink Royal Suit Costume
No gown? Mia's pink skirt suit handles royal day duty instead. Pair a fitted blush or rose-pink jacket with a matching knee-length skirt and a cream camisole, then sheer tights, pearl earrings, a structured bag and neutral low pumps. Long brown hair goes straight with softly turned ends, or use a sleek brown wig. Tidy brows, mascara, pink blush and a satin lipstick. A crown brooch or mini tiara gives the royal signal without crowding the suit. Carry a folder labeled “Royal Schedule” and keep your shoulders back all evening, since that princess-lesson posture is half the joke. Suits are the easy pick for work events and school celebrations.
11. Mia Coronation Gown Costume
A coronation look should feel ceremonial but still let you move. Start with a white or ivory floor-length gown with embroidered trim, fitted sleeves or a structured neckline, and add a light royal-blue or cream cape with decorative clasps. White gloves, pearl drops and silver flats go under the skirt. Brown hair sits in a soft curled updo with a jeweled tiara, and makeup stays refined with glowing skin and rose lipstick. A small scroll tied with blue ribbon beats a bulky prop. Fabric appliqués and iron-on silver trim make a cheap formal dress look grander, but test the trim on a hidden seam first, since many cheap gowns are polyester that puckers under a hot iron. Keep the cape short enough that nobody steps on it.
12. Mia Royal Wedding Dress Costume
For Mia's royal wedding look, choose an ivory gown, either long-sleeved lace or a full-skirted white dress with a fitted bodice. Attach a waist-length veil under the tiara so both stay visible. I sew the veil's comb to the underside of the tiara band, so the two move as one piece and the veil can't drag the tiara backward. Ivory flats or low block heels. Smooth brown curls gather into a low bun with a few soft pieces at the face, then luminous skin, pink blush, subtle liner and rose lipstick. Carry a small bouquet of white faux flowers with blue ribbon, and add a pendant and pearl studs. Keep the train short, or switch to tea-length, if you'll be walking outdoors or dancing.
13. Mia Princess Riding Costume
The riding look is a sharp, practical alternative to gowns. Wear cream riding pants, a white collared shirt, a fitted navy riding jacket and tall black boots, plus black gloves and a velvet riding helmet or an equestrian-style cap. Long brown hair pulls into a low ponytail or a braid at the nape, with natural makeup. Carry a coiled blue ribbon, a riding-club badge or a small grooming brush rather than realistic equipment, and pin a silver crown to the lapel. I'd happily use flat knee-high fashion boots if you don't own riding boots; they're honestly easier to walk in, since real riding boots are stiff until they're broken in.
14. Mia Garden Party Costume
Picture Mia at an afternoon event in Genovia. Wear a pale blue, lilac or blush midi in a tiny floral print with a cropped cream cardigan, pearl earrings, and low pumps or ballet flats. Loose, brushed curls go under a slim satin headband, with peach blush, fluttery lashes and pink lipstick. Short white gloves, a small structured purse and a silver crown brooch, plus a fan or a basket of faux flowers. A light fascinator can stand in for the tiara. Fascinators sit on a thin comb or headband, and the comb holds much better slid in at an angle toward the back of the head than pushed straight down. It's a gentle daytime look for school functions and family parties.
15. Mia Genovian Parade Costume
The parade costume is built on Genovia's royal colors. Wear a white fit-and-flare dress with a royal-blue sash from shoulder to hip, a short blue cape, white gloves and silver low heels or embellished flats. Smooth brown waves sit under a sparkly tiara pinned firmly. Pink blush, lashes and a glossy berry lip. Carry a small bouquet, a mini fabric flag or a blue-and-white ribbon wand. A sash slides off the shoulder all night unless you pin it at the shoulder seam and again at the hip, under the gold trim where the pins hide. For an outdoor parade, add a white long-sleeved top underneath and supportive silver sneakers. The white and blue contrast reads from far away.
16. Mia Airport Princess Costume
Airport Mia mixes royal glamour with funny practical touches. Start with a simple white midi dress and a pale cardigan or light coat, then add white gloves, a silver tiara, oversized black sunglasses and big black headphones. White socks and white sneakers give the deliberately youthful early-2000s finish. Long brown hair goes straight or softly waved under the crown, with rosy blush and pink gloss, since the sunglasses cover most of the face anyway. Pull a small rolling suitcase or carry a travel bag with a handwritten luggage tag, and let a plush gray cat peek out of an open tote. Indoors, swap in lightly tinted costume glasses so you can actually see where you're walking.
17. Queen Clarisse Royal Suit Costume
Queen Clarisse is all composure. Choose a cream, light gray or pastel skirt suit with a structured jacket and knee-length skirt, over a silk blouse with sheer tights, pearl earrings and neat low pumps. Her short silver hair is soft and rounded. Gray and silver wigs show their wefts easily, so part a cropped wig to the side and lift the top with a little teasing at the crown. Classic makeup with defined brows, muted shadow, rose blush and refined pink lipstick. White gloves, a top-handle bag or folded itinerary, and a jeweled brooch on the lapel. Stand tall and keep everything immaculate. She's warm, comfortable and rounds out a family or multigenerational group.
18. Queen Clarisse Evening Gown Costume
For a formal Clarisse, choose a silver, champagne or pale blue evening gown with long sleeves and a flowing skirt, with a matching wrap, a pearl necklace, white gloves and comfortable metallic pumps. Short silver hair gets a polished curl under a refined jeweled crown. Luminous foundation, soft gray shadow, mascara and a mauve-pink lip. A satin clutch and a folding fan. A royal sash can go on for ceremonial events, in a muted color so the gown stays the focus. Breathable fabric and a hem that clears your shoes matter more than sparkle if you'll be on your feet. Aim for calm authority, not fairytale glamour, because that's what sets her apart from Mia's youthful looks.
19. Lilly Moscovitz School Costume
Lilly is the practical, opinionated friend, so her version is sharper than Mia's. Wear a dark plaid skirt, a fitted tee and an oversized cardigan or casual jacket, with opaque tights, chunky black shoes and a crossbody messenger bag covered in pins. Short dark hair goes in a textured bob, or use a chin-length brown wig with side-swept pieces. Dark mascara, smudged liner and neutral balm. A toy microphone, notepad or cardboard video camera hints at her student-media streak, and a handmade badge with a playful made-up slogan adds character. Badge pins pull holes in thin cardigan knits, so back each one with a small square of felt inside. Next to Mia, share the blue school colors but give Lilly the heavier shoes and louder accessories.
20. Lana Cheerleader Costume
Lana is the bright, polished contrast to Mia's rumpled uniform. Wear a blue-and-white athletic top with a matching pleated skirt, ankle socks and clean white sneakers, at a neckline and length that suit your event. Long blonde hair goes in a high ponytail with a blue ribbon, with pink blush, defined lashes and glossy pale lips. Pom-poms and a light faux ice cream cone made from paper or felt give the movie joke. Cut a letter patch from felt and attach it with fashion tape or a few stitches; felt letters glued onto a slick polyester top peel off within hours. Stud earrings and a confident smile. For cold weather, white leggings and a matching varsity jacket keep the uniform colors.
21. Lana Beach Party Costume
Lana's beach look is early-2000s through and through: a pink mock-neck top with a matching polka-dot midi skirt, and flat pink sandals or white platform sneakers. Straight blonde hair gets flipped ends and two small front clips. Glossy makeup with rosy cheeks, shimmer, mascara and bubblegum-pink lipstick. Carry a toy microphone and a small pastel shoulder bag, with oversized sunglasses pushed up on your head. Mock necks in cheap stretch fabric can feel tight at the throat after a few hours, so size up if you're between sizes. A cropped pink cardigan covers it outdoors, and the pieces stay wearable long after Halloween.
22. Michael Moscovitz Musician Costume
Michael is the low-effort pick for someone who doesn't want to dress up much. Wear a dark graphic tee with no visible logos, straight-leg jeans and an open overshirt or zip jacket, black canvas sneakers and a simple watch. Short dark hair, slightly tousled, and no makeup needed. Carry a light toy keyboard, a sheet-music folder or a cardboard guitar with rounded edges, and clip a cardstock backstage pass to a lanyard. On his own he's simply a guy in jeans, so he really needs Mia beside him; add a navy accent that matches her uniform. Leave royal accessories off entirely.
23. Joe Royal Security Costume
Joe blends chauffeur formality with calm royal security. Wear a black suit, crisp white shirt, dark tie and polished black shoes, with a long black overcoat outdoors, and comb short dark or salt-and-pepper hair neatly. Dark sunglasses are fine only if you can see safely indoors. For the coiled earpiece, I run flexible costume cord down inside the collar and tape the end to the shirt so it doesn't swing loose. Oversized prop car keys, a folded schedule or a small clipboard, a blue-and-gold lapel pin for the fictional royal household and black gloves finish him. Put him next to Queen Clarisse and everyone gets it, and the suit goes straight back in the wardrobe afterward.
24. Paolo Makeover Stylist Costume
Paolo should be theatrical and funny but easy to wear. Start with a fitted black shirt, black trousers and a patterned satin vest or dramatic blazer, sleek loafers and a bright pocket square. Dark hair goes slicked back, or use a short glossy wig. Groomed brows, light complexion makeup and a touch of contour. His kit is the costume: a wide-tooth comb, clean makeup brushes and an empty spray bottle in a small stylist's case, all light plastic with rounded edges, plus a tape measure around the neck and a handwritten makeover appointment card. Keep that spray bottle empty, because someone will try it on a friend. Pair him with pre-makeover Mia and the duo tells the story at a glance.
25. Mia And Michael Couple Costume
This couple pairs the school uniform with easy musician clothes. Mia wears the light blue shirt, plaid skirt, navy tie, knee socks, black shoes, wire-frame glasses and big brown curls, with minimal makeup and a diary or backpack. Michael wears a dark tee, jeans, a casual jacket and black sneakers, with tousled dark hair and a toy keyboard or sheet-music folder. Matching blue accents or handmade school badges connect you. Neither of you needs formalwear, so it's cheap and comfortable for a long night. For a later-story version, swap Mia's glasses for a small tiara and keep the uniform.
26. Mia And Nicholas Couple Costume
For a royal couple, Mia wears a pale blue or white floor-length gown, a silver tiara, pearl earrings, long brown curls and low metallic heels, with soft pink makeup and a small clutch. Nicholas wears a black or navy formal suit, white shirt, elegant tie and polished shoes, with neatly styled dark hair. I'd hold his blue pocket square up against her dress in daylight before you commit, since a near-match looks worse in photos than a clear contrast. Carry matching made-up palace invitations or pin small crowns on both outfits. Skip long trains and heavy capes so you can actually dance. At a formal event, the tiara and the coordinated details explain the theme on their own.
27. Mia Before And After Duo Costume
This duo turns the makeover into a costume concept. One person wears a loose blue school shirt, plaid skirt, crooked tie, knee socks, chunky shoes, wire-frame glasses and big brushed-out brown curls, with minimal makeup, a backpack and a doodled diary. The other wears a sleek white dress, silver heels, white gloves, a sparkling tiara, straight brown hair, rosy makeup and pink gloss, plus the black sunglasses and headphones. I always match the brown hair color exactly between the two of you. If one wig is warm brown and the other ashy, people read two different characters. Matching silver crown pins help, and standing back-to-back for photos shows off the two silhouettes.
28. Mia And Lilly Best Friend Costume
Mia and Lilly share a school but not a personality, and the costumes should show it. Mia gets the light blue button-down, blue plaid skirt, navy tie, black knee socks, loafers, full brown curls, wire-frame glasses, natural makeup and a diary. Lilly gets a darker top, plaid skirt, oversized cardigan, opaque tights, chunky black shoes, a short dark bob, smudged liner, a messenger bag and a toy microphone. Matching blue hair ribbons or made-up school patches connect you. If I can't find two plaids that go together, I put Lilly in a solid dark skirt instead, because two clashing plaids side by side look like a mistake. A light cardboard video camera with rounded corners makes for funny photos.
29. Mia Clarisse And Lilly Trio Costume
Mia, Queen Clarisse and Lilly give you three distinct takes on the films' style. Mia wears the blue plaid uniform, knee socks, loafers, fluffy brown curls, glasses and light makeup. Clarisse has a cream skirt suit, pearl earrings, white gloves, low pumps, short silver hair, rose lipstick and a structured handbag. Lilly wears a dark cardigan, casual top, plaid skirt, tights, chunky shoes, a short brown bob, subtle liner and a messenger bag. Give Mia a diary, Clarisse a royal schedule and Lilly a toy microphone. Put Mia in the middle for photos, since she's the one people recognize first. Shared blue details hold the three together even though no two silhouettes match.
30. Genovian Pajama Party Group Costume
A royal sleepover is an easy group theme. Each person picks a pajama set in blue, pink, lavender, mint or cream, with long pants, button-up tops, robes and secure slippers. Add light tiaras, satin sleep masks and playful sunglasses, with hair anywhere from loose curls to tidy updos. Makeup can vary, though rosy cheeks and a little gloss on everyone make the group look unified. Props are personal, from pillows and diaries to plush animals or fans. One person plays Mia in blue pajamas and the rest are royal guests. Agree on colors in a group chat beforehand, or two people always turn up in the same pink. It's a comfortable choice for dorm events and family parties.
A Plaid Uniform From the Thrift Rack
Mia, Lilly and most of the group looks rely on a school uniform, and a packaged costume version is rarely the best route. Bagged costume uniforms tend to use thin, shiny fabric that looks cheap in photos.
- I look for a pleated plaid skirt in the women's or girls' section of a thrift store. Wool or a wool blend hangs best and creases less than thin polyester.
- If the skirt is too long, fold the waistband over once or twice and pin it at each side seam. The pleats stay intact and you can let it back down later.
- A men's light blue oxford shirt in a small size gives the baggy pre-makeover fit, while a fitted women's shirt suits the after version.
- Any plain navy tie will do, knotted loosely a few inches below the collar. A clip-on is easier for kids and won't come undone.
- Knee socks slide down by the end of the night. A strip of fashion tape at the top of each sock, or a narrow elastic hidden in the fold, keeps them up.
Props You Can Make the Night Before
The prop is what turns a plaid skirt into Mia, so I always give it an evening.
- The diary: cover any notebook in fabric or wrapping paper, write a few handwritten entries inside and add a ribbon bookmark. People do open it.
- The crown pin: glue a small tiara charm to a brooch back. Hot glue lets go of smooth metal, so use a jewelry adhesive or two-part epoxy and let it cure overnight.
- The headphones: any big over-ear pair works. If they're real headphones, cover the logos with black tape.
- The royal schedule: a plain folder with a printed label and one page of made-up appointments inside. It gives Clarisse and pink-suit Mia something to do with their hands.
Which Mia Will You Be?
Princess Diaries costumes work best when they mix early-2000s nostalgia with a few royal details. Keep it simple with Mia's school uniform, go glamorous with the white gown and headphones, or put a whole group in royal pajamas. Build every look from head to toe, with the hair, makeup, shoes and at least one prop people recognize. Thrift stores and your own closet supply most of the clothes, and homemade sashes, diaries and crown pins cost very little. Solo, as a couple or with a whole group of friends, there's a version here comfortable enough to wear all night.
Related posts:
