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Halloween Costume Guide

Siobhán Súilleabháin Halloween Costume Guide (The Banshees of Inisherin)

Siobhán’s 1950s rural Irish wardrobe: red wool coat, vintage dress, lace-up heels, and a long brown wave. A quieter costume build with a strong film behind it.

Kerry Condon The Banshees of Inisherin Irish Oscar
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Quick Answer: The Siobhán costume is a mid-century Irish look built around a red wool coat and vintage dress.
  • Red Long Wool-Blend Winter Coat (essential)
  • Vintage Dress (essential)
  • Brown Wavy Wig
  • Leather Lace-Up Heel Pump
  • Yellow Retro Overcoat

Siobhán Súilleabháin runs the island’s small library and spends most of The Banshees of Inisherin trying to leave it. The red coat is her most visible costume detail and the one fans of the film will place fastest. Kerry Condon won the Academy Award for Best Supporting Actress for this role at the 95th Oscars in 2023, which keeps the film in conversation even three years on (Wikipedia). The costume is subtle enough that without the coat, most people at a general party will not place the character.

Items Total5 Items
DifficultyEasy
Vibe1950s Rural Irish
Cost$55–$130

Siobhán Súilleabháin Halloween Costume Items

Siobhán Súilleabháin Halloween costume infographic from The Banshees of Inisherin showing the red wool coat, vintage dress, brown wavy wig, lace-up heels, and yellow overcoat

Siobhán Costume Items

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Siobhán Kerry Condon Banshees of Inisherin 1950s Irish
  • 1 Brown Wavy WigSiobhán’s hair is long, dark brown, and wavy throughout the film. If yours is already close, skip this. A wig that sits unevenly or has an obvious synthetic shine will be the first thing people notice, and not in a good way. Check the reviews for natural-looking wave before ordering.
    See on Amazon
  • 2 Vintage Dress (essential)The base layer sets the period. You want something that reads as 1950s rural rather than 1950s formal: a plaid, a muted floral, or a plain dress in green, brown, or navy. Nothing fitted, nothing shiny. This is the item where a thrift store find often works better than something ordered new, because new vintage-style dresses tend to look exactly like that.
    See on Amazon
  • 3 Red Long Wool-Blend Winter Coat (essential)This is the item the costume depends on. The red coat is Siobhán’s most consistent visual identifier in the film, and it is what fans will place first. It needs to be long, structured, and read as proper outerwear rather than fashion. A short or unlined coat loses the period weight. If a vintage silver brooch is pinned to the lapel, the reference gets more specific.
    See on Amazon
  • 4 Leather Lace-Up Heel PumpPeriod-appropriate and more comfortable than most heeled options for a long evening if the sole has any cushion. Make sure they are fully laced before leaving. A half-laced shoe reads as an accident, not a detail.
    See on Amazon
  • 5 Yellow Retro OvercoatSiobhán also appears in a yellow coat in the film. It is a good alternative if you are going to an outdoor event where the red coat would be cold, or if you want to switch between the two across the night. You do not need both. If you are choosing one, the red coat is the stronger character reference.
    See on Amazon
Siobhán Súilleabháin in a green plaid dress and red cardigan outside a stone thatched cottage with a wicker laundry basket, with a black donkey grazing in the foreground

How to Style the Siobhán Súilleabháin Halloween Costume

The red coat lands first, and it needs to look like outerwear rather than a costume piece. A coat that is too short, too fitted, or clearly modern-cut makes the vintage dress underneath read as a mismatch rather than a period look. The brooch on the lapel is a small detail, but it pulls the whole thing toward a specific visual reference from the film. Without it, you are wearing a red coat. With it, you are wearing Siobhán’s red coat. If the coat looks fashionable rather than functional, the 1950s Irish setting does not come through.

There is a moment near the end of the film where Siobhán has clearly made her decision to leave and is just waiting for the ferry. She is not dramatic about it. She has been the most sensible person on the island for the entire runtime, and she is sensible about leaving too. That quality, patient and certain and slightly done with everyone, is easy to carry at a party without any props or lines. It is also funnier the longer the night goes on.

The brooch detail earns the recognition

Fans of the film will know the red coat. The vintage silver brooch pinned to the lapel is what moves it from “woman in a red coat” to a specific Siobhán reference. Most silver vintage brooches from a charity shop or jewellery box will work. It does not need to be an exact match. The placement matters more than the style: left lapel, near the collar. If you do not have one, the coat still works, but you lose the one detail that signals to film fans that you have actually watched it.

Wool coats get warm indoors fast

A long wool-blend coat is excellent outdoors and genuinely miserable inside a crowded venue after thirty minutes. Plan for somewhere to put it. If the coat comes off, the dress and heels still read as period-appropriate, but the character reference gets much weaker. The yellow overcoat is lighter and a more practical option if most of your evening is indoors.

Siobhán Súilleabháin Group Halloween Costume Ideas

Group Idea: The Inisherin Islanders

Siobhán, Pádraic, Colm, Dominic

Excellent group for a film-literate crowd because the four characters together tell the whole story visually without anyone having to explain it. Pádraic needs to look like a sad Irish farmer, Colm like a disappointed musician, and Dominic like a young man who has had a genuinely terrible year. If anyone in the group does not commit to the specific character details, this reads as “four people from an island” rather than the film.

Siobhán Pádraic Colm Dominic

Group Idea: The Literary Intellectuals

Siobhán, Belle, Hermione Granger, Enola Holmes

Might work, but the connection is loose enough that you will need to pitch the theme to every person who asks. Siobhán is a librarian who wants a more intellectual life. Belle, Hermione, and Enola Holmes are all defined by reading and thinking. The problem is that three of the four costumes are from major franchises that most people will recognise immediately, and one is from a 2022 arthouse film that requires a certain type of audience to land. The visual variety is actually fine; the concept requires more explanation than it is worth at a general party.

Siobhán Belle Hermione Granger Enola Holmes

Group Idea: The Kerry Condon Collection

Siobhán, Octavia of the Julii, Stacey Ehrmantraut, Pamela

Strong concept if everyone in the group is a genuine Kerry Condon fan, because the meta-joke is the entire point and it only lands if all four costumes are clearly from different productions. This works at a film or TV convention. At a general party, three of the four characters are niche enough that the group will spend most of the night explaining who they are, which is fine if that is the kind of night you want.

Siobhán Octavia of the Julii Stacey Ehrmantraut Pamela

Group Idea: The Sovereign Siobhas

Siobhán Súilleabháin, Siobhan Roy, Siobhán (Crying Freeman), Siobhan Kelly

Might work, but only at events where at least some people are deep enough into pop culture to recognise multiple Siobháns by costume alone. Siobhan Roy from Succession is the most recognisable of the four. The others range from moderately niche to very niche. The concept is genuinely funny if it lands, and completely invisible if it does not. This is a group idea for people who are committed to a bit.

Siobhán Súilleabháin Siobhan Roy Siobhán (Crying Freeman) Siobhan Kelly

Group Idea: Craving a Life Beyond

Siobhán, Maeve Wiley, Lady Bird McPherson, Rose DeWitt Bukater

Might work, but this is a theme that requires the crowd to do a lot of interpretive work. All four characters want more than their current situation allows, and all four eventually leave. Maeve Wiley and Rose are recognisable enough to anchor the group visually. Siobhán and Lady Bird are more niche picks that will resonate with specific people and go unnoticed by everyone else. The concept is cohesive on paper. In a loud venue, it is invisible.

Siobhán Maeve Wiley Lady Bird McPherson Rose DeWitt Bukater
Close-up of Siobhán Súilleabháin from The Banshees of Inisherin wearing a red coat with a vintage silver brooch on the lapel over a patterned blouse, with a blurred coastal background

ALL THE BANSHEES OF INISHERIN & SPIN-OFF COSTUME IDEAS

Every The Banshees of Inisherin costume guide on CostumeRealm.

Dominic Kearney costume

Dominic Kearney

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Colm Doherty costume

Colm Doherty

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Burt Fabelman

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Siobhán Súilleabháin Halloween Costume DIY Tips

Building the Look on a Budget

Most of this costume can be sourced secondhand without losing anything important. The coat is the one item worth spending on because fit and length matter more than price.

  • Vintage dress: thrift stores first. A real vintage dress in a muted plaid or floral will look more accurate than a new vintage-style dress at twice the price.
  • Red coat: this is not the place to cut corners. A short or clearly modern coat undermines everything else. Buy or borrow one that is long, structured, and reads as proper outerwear.
  • Brooch: charity shop jewellery box. Silver, vintage-looking, nothing too ornate. Positioned on the left lapel near the collar.
  • Heels: check your own wardrobe first. Any lace-up heel in brown or black works. The specific style matters less than the lacing.
  • Yellow coat: skip it unless you specifically prefer it or are going somewhere very warm. One coat is enough.
  • Wig: only buy it if your hair is clearly not a match. A bad wig is worse than no wig.

Playing Siobhán at the Party

Siobhán’s defining quality is that she is consistently the most reasonable person in any room, which she is quietly exhausted by. That is an easy energy to maintain for a few hours.

  • When someone asks who you are: “The librarian from The Banshees of Inisherin. I leave at the end.” People who have seen the film will laugh. People who have not will move on quickly, which is fine.
  • If they ask what the film is about: “Two friends have a falling out and it gets worse from there.” That is accurate and does not require a ten-minute plot summary.
  • The character reads as someone who has already mentally left the party. That is an extremely low-maintenance character note to hold all night.
  • Carrying a small book is optional but gives you something to do and reinforces the librarian detail without any explanation needed.

Siobhán Súilleabháin Halloween Costume: FAQ

The red coat is the centrepiece. Wear it over a vintage-style dress, add leather lace-up heels, and style or add a long brown wavy wig. Pin a vintage silver brooch to the left lapel if you have one. The yellow overcoat is an alternative for a warmer or outdoor setting. Both looks draw from 1950s rural Irish women’s dress: layered, practical, and period-specific.

The Banshees of Inisherin has a dedicated following among film fans, and Kerry Condon’s Oscar win for this role keeps it in awards conversations. Recognition at a general party will depend heavily on the crowd. Without the coat, the costume reads as a period Irish look rather than a specific character, which matters if being recognised is part of the plan.

Siobhán’s most quoted lines come from her frustration with island life and her determination to leave. She is consistently direct about wanting something more than Inisherin can offer, and the film credits her as one of the few characters who actually acts on that. Her departure from the island at the end is the clearest statement she makes across the entire film, and it does not require a single word.

Siobhán is played by Kerry Condon, an Irish actress who won the Academy Award for Best Supporting Actress for this role at the 95th Oscars in 2023. She is also known for playing Octavia of the Julii in the HBO series Rome and Stacey Ehrmantraut in Better Call Saul. The film was written and directed by Martin McDonagh (IMDb).

Siobhán’s wardrobe reflects 1950s rural Ireland: vintage dresses in muted plaids and greens, a structured red wool coat worn with a silver brooch on the lapel, and a yellow overcoat in warmer scenes. The heels are leather and lace-up. Her long brown wavy hair is a consistent detail throughout. The palette is earthy and practical, nothing frivolous.

No. If your hair is already long, dark brown, and naturally wavy, skip the wig. A close natural match is better than a synthetic wig at the same length. The wig is only worth buying if the difference between your hair and Siobhán’s is significant enough to affect the read.