Halloween Costume Ideas – Costumes Beginning with O

Have you ever been to an alphabet party? When I was in my early 20s they were all the rage, somehow everytime I was invited to one it was always a P party which meant dressing up as something beginning with the letter P. You can choose any letter of the alphabet however and today I’ve chosen the letter O.

From Oscar the Grouch to the Oreo cookie there are lots of different costume ideas that start with the letter O – which one will you choose?

Fancy dress parties or costume parties are so much more fun when they’re themed, but you don’t always want to have an 80s party, 1920s dress up event or even a Star Wars themed party. Choosing a letter to base your party around is fun because seeing how people interpret it can be really interesting…..some people really know how to think outside of the box.

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Costumes Starting with O – The List

  • Obi Wan Kenobi – I think everyone knows someone who is obsessed with Star Wars so you can breathe easy that they can break out a Star Wars costume that starts with the letter O
  • Octopus
  • Olive Oyl – I remember watching Popeye cartoons growing up with Olive Oyl as his girlfriend – I can’t remember much about her (although I can’t get the ‘I’m Popeye the sailor man’ song out of my head now!), but the costume is instantly recognizable.
  • Oompa Loompa – the orange complexioned Oompa Loompa’s were from one of my favorite childhood books – Charlie and the Chocolate Factory.
  • Opera Singer
  • Operation – the game – I don’t know many people who haven’t played this game at least once during their childhood and I was tickled pink when I saw a photo online of someone dressed up in a homemade operation costume – awesome idea!

 Rasta Imposta Men’s Octopus Costume Operation Board Game Adult Costume Forum Novelties Orange Costume


  • Optimus Prime – From the Transformers, I think this is a cool costume idea if you want to go with a readymade costume idea.
  • Orange
  • Orang-utan
  • Orc
  • Oreo – a great diy costume idea, the best one I have seen has even published a how to guide for you – DIY Oreo Cookie Costume.
  • Orion Slave Girl – As seen in the original (and dare I say best!) Star Trek series the Orion Slave Girl was a green skinned girl in a skimpy bikini inspired outfit which is very popular at comic-con conventions and other sci-fi events.
  • Orphan Annie
  • Oscar Statue
  • Oscar the Grouch – An instantly recognizable Sesame Street character that will be recognised by young and old alike.
  • Owl
  • Ozzy Osbourne – this is a simple costume to carry off, simply don a long black wig, sunglasses and wear black.

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