I’m hoping at least one of my kids will choose one of these amazing geeky Halloween costume ideas — which is to say that no, my kids still haven’t made up their minds about their Halloween costumes this year. Hello, kids! Time for a decision! While cosplay isn’t part of our lives (yet?), I still think it would be pretty fun to go door-to-door collecting candy with Finn the Human or a Dalek one of these years.

So, fellow geeky parents, check out these awesome and fairly easy geeky Halloween costumes for kids. I’m pretty sure you can pull these off without too much struggle, or any space lasers or time-travel skills..

This post contains affiliate links and some purchases may generate a small commission to help support our work at no additional cost to you. 

This post has been updated for 2021

Related: More than 75 last-minute Halloween costume ideas you can pull together in a snap

Doctor Who Halloween Costume for Kids

Geeky Halloween costumes for kids: Dr. Who by Keelhaulrose2 on Buzzfeed


The pinnacle of geek culture has to be The Doctor. Rather, the lord of all geek culture. If you’re a fan, you can pull together this 10th Doctor Doctor Who Halloween costume if you’ve got a sonic screwdriver lying around the house somewhere. Then, just cap off a raid on Mom or Dad’s closets for the rest of the look, with inspiration from by Keelhaulrose2 via Buzzfeed.

Related: 7 helpful tips for taking great Halloween pics of your kids

Finn and Jake from Adventure Time Costume

Geeky Halloween costumes for kids: Finn the Human from Adventure Time

I’m pushing hard for a Finn the Human from Adventure Time to join me trick-or-treating this year. I love this handmade costume I spotted on Pinterest, which uses the shape-shifting Jake as the trick-or-treat bucket. If you don’t think you can pull off a DIY like this one, you can find some inexpensive ones at our affiliate Amazon.

(Note: we couldn’t find the correct source for this photo. If it’s yours, please let us know so we can credit you properly!)

Eleven Stranger Things Costume

Geeky Halloween costumes for kids: Eleven from Stranger Things at Say Yes

Whether or not your kids are old enough for Stranger Things, prep them by by dressing your toddler up in this DIY Eleven costume we found at Say Yes. Feeling extra crafty? Attach a strap to that Eggo box to use as her trick-or-treat bag for the night.

Rey Star Wars Costume

Geeky Halloween costumes for kids: Rey from Star Wars costume via Chameleon Girls on Etsy
You can pull off a pretty amazing Rey Halloween costume with one click to Etsy shop Chameleon Girls. If you want to DIY, you can always find some help from one of the million Pinterest tutorials out there, but it’s hard to beat the convenience of a ready-made, handmade costume. Besides, our kids will be happy to find any excuse to wear this long after Halloween is over.


Baby Mandrake Harry Potter Halloween Costume

Geeky Halloween costumes for kids: New-sew Baby Mandrake costume at True Blue Halloween


This no-sew baby Mandrake costume we featured at Cool Mom Picks in a roundup of easy new-sew Halloween costumes for babies — is made easier thanks to a free printable from True Blue Halloween. It couldn’t be easier for Harry Potter fans. Just be sure to plug your ears if your baby mandrake happens to scream. You know what will happen if you don’t.


Baby Tyrion Lannister Game of Thrones Costume

Geeky Halloween costumes for kids: Baby Tyrion Lannister, photo by Leniebelle Gallardo

We featured an entire roundup of cool Game of Thrones costumes for kids over at Cool Mom Picks, from Jon Snow to Khaleesi to an Iron Throne stroller. Yes, even if they’re too young to watch. But this baby Tyrion Lannister, snapped by mom Leniebelle Gallardo, is absolute perfection — from that Hand of the King pin to the Blackwater scar. The brilliant vest is made by the Little Ivie Rose Shop. This kid drinks (a bottle) and knows things.

Baby Pokéball Halloween Costume

Geeky Halloween costumes for kids: Pokeball at Say Yes

Got 10 minutes and some scraps of felt? Then you can easily pull off this simple Pokeball costume we found at Say Yes. But don’t limit this idea to your adorably chubby baby. A pair of white jeans and red t-shirt will make this work for any member of your family.’

Related: 12 more easy, no-sew Halloween costumes for babies and kids

R2D2 Halloween Costume

Geeky Halloween costumes for kids: R2D2 at Under the Sycamore

All you need is one of mom or dad’s plain white tees and a blue marker to make this DIY R2D2 costume we spotted over from Ashel Anne at Under the Sycamore. Sure, it may not be as spot-on accurate as the store-bought version, but so what? We think it’s pretty awesome.

Related: 13 super easy no-sew costumes for babies and toddlers

Baby Ghostbuster Costumes

Geeky Halloween costumes for kids: Ghostbusters at The House that Lars Built

Last year I geeked out over this adorable Ghostbusters Halloween costume for babies at The House that Lars Built, which we shared in our post on easy Halloween costumes for kids all made out of pajamas for kids. You can age this one up with leggings or long PJs and a t-shirt — we’d start by checking Primary.com, which is ground zero for solid, well-made, affordable baby and kids pjs that last. The snap or zip-up footie PJ like the one shown here could totally work too.

Elliot and ET Costume

Geeky Halloween costumes for kids: Elliott and E.T. at And We Play

Now that my kids are finally old enough to watch E.T. it was our movie night choice recently. And I’m hoping one of my kids decides to dress up in an Elliott Halloween costume, because this idea from And We Play couldn’t be easier. You still have time to get an E.T. plush doll from  Amazon or a local toy shop before Halloween, or you could just wrap up any brown stuffed animal. It will be dark. No one will notice.

Related: Notable women in STEM Halloween costumes for kids

Kids’ Dalek Costume

Geeky Halloween costumes for kids: Dalek at One Half World

If your kid tends to side with the bad guy instead of the hero, they’ll love this kids’ Dalek costume at One Half World. There are hundreds of amazing Cosplay Dalek costumes on Pinterest, but this one stood out to be because it looked so doable. And with Nicole’s step-by-step tutorial, it might actually be. Just save your Amazon boxes!