This list includes 36 Male costume ideas that start with O, from “Obelix” to “Ozymandias”. Many entries are pop‑culture characters, occupations, and historic or mythic archetypes for Halloween and cosplay.

Male costume ideas that start with O are themed looks for men, covering characters, occupations, animals, and historical roles. Notable examples include “Obelix” from the Asterix comics and “Ozymandias”, a name used in poetry and comics.

Below you’ll find the table with origin and required pieces.

Origin: Quick tag that tells you where the costume comes from so you can choose by theme or fandom.

Required pieces: Short list of three to six essential items to buy or DIY, helping you assemble the costume quickly.

Male costume ideas that start with O

NameOriginRequired piecesEstimated cost (USD)
Obi-Wanfictional — Star Warsbrown robe, tunic, belt, lightsaber, boots50–200
Optimus Primefictional — Transformershelmet/mask, chest armor, red/blue jacket, gloves, boots80–400
Oppenheimerhistorical — scientist1940s suit, tie, round glasses, pocket watch or briefcase, haircut styling40–150
Odinmythic — Norsecloak, horned or winged helmet, long beard, spear or staff, eye patch40–200
Oompa Loompafictional — Roald Dahlorange body paint, white overalls, green wig, brown shoes, gloves30–80
One Punch Manfictional — animeyellow jumpsuit, white cape, red gloves, bald cap, red boots30–120
Orcfictional — fantasygreen/brown face paint, tusk prosthetics, leather armor pieces, fur cloak, weapon prop40–200
Olaffictional — Disneywhite tunic or snowman suit, carrot nose, twig arm props, coal buttons, hat30–100
Othellofictional — ShakespeareVenetian doublet, cloak, sword, feathered hat, boots40–150
Odysseusmythic — Greektunic/robe, leather belt, laurel or helmet, sword or spear, sandals30–150
Ozymandiasfictional — Watchmendark suit, cape (optional), blonde wig, symbolic ring50–150
Oceanographeroccupationkhaki shirt, cargo pants, field vest, binoculars, notebook30–100
Oscar the Grouchfictional — Sesame Streetgreen fur suit or green clothing, trash can prop, eyebrow makeup, gloves30–120
Outlawarchetype — Wild Westduster coat, cowboy hat, bandana, toy revolver, boots30–150
Officeroccupation — genericuniform shirt, badge, hat, duty belt, handcuffs30–150
Ostrichanimalinflatable or full-body ostrich suit, beak/headpiece, leg covers30–180
Oxanimalhorned headpiece, brown fur vest, tail, hooved shoe covers25–80
Owlanimalfeathered cape or jacket, owl mask, talon gloves, beak accessory30–120
Ocelotfictional — video gametrench coat or leather jacket, revolver prop, gloves, sunglasses, ponytail wig (optional)40–150
Onimythic — Japanesehorned mask, kimono or robe, club (kanabo) prop, red/blue body paint30–150
Orpheusmythic — Greektunic, laurel, lyre or small harp prop, sandals, cloak30–120
Oberonfictional — Shakespeareregal doublet, crown, cloak, wand or scepter50–200
Orange Power Rangerfictional — Power Rangersorange ranger suit or jacket, helmet or mask, gloves, boots40–250
Oddjobfictional — James Bonddark suit, bowler hat, metal-looking throwing hat prop, gloves, tie30–150
Oogie Boogiefictional — The Nightmare Before Christmasburlap sack suit, burlap mask, dice prop, green lighting makeup40–200
Octopusanimaltentacle costume or cloak, headpiece, suction-cup detailing, matching gloves30–150
Odofictional — Star Treksecurity uniform, bald cap, shapeless neutral-tone makeup, communicator badge40–150
Oliver Twistfictional — DickensVictorian shirt, waistcoat, flat cap, trousers, scarf30–100
Oscar Wildehistorical — writervelvet suit or frock coat, cravat, pocket watch, cane, floral boutonniere40–150
Old Hollywood Stararchetype — 1920s–50stuxedo or suit, slicked hair, cane or cigarette holder, pocket square50–300
Oogwayfictional — Kung Fu Pandatortoise headpiece, long robe, staff, white beard40–150
Ozfictional — The Wizard of Ozemerald robe or suit, top hat, cane, theatrical makeup or beard40–200
Osirismythic — Egyptiannemes headdress or crown, Egyptian collar, crook and flail props, robe40–200
Obelixfictional — Asterixstriped trousers, wide belt, blue helmet or cap, prop menhir or club40–150
Otteranimalbrown fur jumpsuit or vest, otter headpiece, tail, whisker makeup30–120
Octavianhistorical — RomanRoman toga or tunic, laurel wreath, gladiator sandals, sash30–150

Descriptions

Obi-Wan
Classic Jedi costume: layered tunic, cloak and lightsaber make this instantly recognizable for Star Wars fans and easy to DIY or buy premade.
Optimus Prime
Iconic robot leader look—full armor or simple mask and chest panel options suit cosplayers and Halloween-goers alike.
Oppenheimer
Subtle, cinematic costume: a period suit, vintage accessories and slicked hair recreate the famous physicist’s look.
Odin
Regal and dramatic Norse god outfit—mix mythic props and a heavy cloak for a powerful, masculine costume.
Oompa Loompa
Fun and instantly recognizable for groups — requires body paint and wig; great for couples or themed parties.
One Punch Man
Saitama’s minimal superhero look is easy to DIY: bald head, yellow suit and cape make it a standout, cosplay-friendly choice.
Orc
Versatile fantasy staple—face paint, tusks and rugged armor create a battle-ready orc for conventions and Halloween.
Olaf
Warm-hearted, goofy snowman costume that’s family-friendly and easy to assemble with simple props and a padded suit.
Othello
Dramatic period costume from the Shakespearean tragedy—perfect for literary-themed events or elegant masquerades.
Odysseus
Classic Greek hero look—tunic and simple armor pieces evoke the wanderer king for historical or mythic parties.
Ozymandias
Stylish and mysterious Watchmen costume: tailored suit with subtle heroic or villainous props for comic fans.
Oceanographer
An easy, modern costume for science lovers—field-ready clothing and accessories make this practical and approachable.
Oscar the Grouch
Playful, trash-can-dwelling character—green fur and a can prop create a nostalgic, humorous costume.
Outlaw
Rugged Western look that’s customizable—bandana and hat instantly signal outlaw vibes for parties and themed nights.
Officer
A straightforward uniform costume that’s easy to source; specify police, security or military variations for clarity.
Ostrich
Novelty and comedic option—inflatable or mascot-style suits make this a hilarious party staple.
Ox
Simple rustic animal costume—horns and fur pieces provide an easily assembled barnyard look.
Owl
Mysterious, stylish costume—feathers and a mask can be elegant or creepy depending on makeup and colors.
Ocelot
From games to fashion, Ocelot-inspired looks range from animal prints to the revolver-wielding character’s trench coat and attitude.
Oni
Striking folkloric demon costume—bold paint and a fearsome mask create an intense cosplay or Halloween look.
Orpheus
Mythic musician costume—simple classical garments and a lyre evoke the legendary poet and singer.
Oberon
Fairy-king elegance from A Midsummer Night’s Dream—ornate fabrics and crown create a theatrical, royal costume.
Orange Power Ranger
Bright, action-ready costume for fans; full suits or themed jackets work for parties and cosplay.
Oddjob
Classic Bond henchman costume—recognizable for the lethal hat and slick suit combo.
Oogie Boogie
Grotesque yet playful villain costume—burlap texture and dice props make this a standout Halloween pick.
Octopus
Eye-catching sea creature costume—multi-tentacle suits or DIY tentacles provide dramatic movement.
Odo
Shape-shifting constable from DS9—costume focuses on a uniform and distinctive bald, smooth look.
Oliver Twist
Classic Dickensian orphan look—great for literary or period-themed parties with easy thrift-store sourcing.
Oscar Wilde
Dandy aesthetic—Victorian flair and witty persona make this literary costume stylish and recognizable.
Old Hollywood Star
Glamorous retro look—think tux, polished hair and suave accessories for a red-carpet vibe.
Oogway
Wise, gentle kung fu master costume—robe and wise-elder props capture the beloved character’s spirit.
Oz
The Wizard persona offers many styles—from grand stage magician to mysterious figure behind the curtain.
Osiris
Ancient Egyptian god costume—ornate collar and headdress make for a striking, culturally rooted look.
Obelix
Beloved comic book strongman—big belt, striped pants and a menhir prop create a humorous, bold costume.
Otter
Cute and approachable animal costume—soft fur pieces and facial makeup make this an easy option.
Octavian
Roman-statesman look (name invokes Octavian/Augustus)—classic toga and laurel create imperial gravitas.
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