---
name: "Sion Trefor"
canonical: "https://film.one/person/sion-trefor"
fi1m_id: "sion-trefor"
tmdb_id: 3967266
roles: ["Composer"]
reviewed_on_fi1m: 3
average_fi1m_score: 76
average_over: 3
updated: "2026-09-24T12:09:09.221180+00:00"
licence: "© Fi1m Ltd. Written by AI under a human editor; checked against sources before publication. Quote with attribution and a link to the canonical URL."
---

# Sion Trefor

## Identity

Sion Trefor

- **Canonical:** https://film.one/person/sion-trefor
- **Type:** Person
- **Fi1m ID:** sion-trefor
- **TMDB ID:** 3967266
- **Same entity:** https://www.themoviedb.org/person/3967266

Composer.

## Details

- **Work:** Composer
- **Active:** 2024–present
- **Fi1m against the critics:** 76 to 77 across 3 titles
- **Score spread:** 0 at 80+, 3 at 60–79, 0 under 60
- **Genres:** Drama 3, Crime 2, Action & Adventure 1
- **Elsewhere:** https://www.themoviedb.org/person/3967266

## Streaming the US now

- **Netflix:** [*Toxic Town*](https://film.one/tv/toxic-town.md) (77), [*Legends*](https://film.one/tv/legends.md) (74)
- **Disney+:** [*Say Nothing*](https://film.one/tv/say-nothing.md) (77)

For United States; add `?region=XX` for another country.

## Biography

Sion Trefor is a composer and multi-instrumentalist. He composed the scores for the FX series *Say Nothing* (2024), the Netflix series *Toxic Town* (2025) and *Legends* (2026).

His other credits include the BBC series *Death Valley* (2025), the Welsh-language feature *Y Swn* and the Netflix series *How to Get to Heaven from Belfast* (2026). Trefor runs a composition and production studio in Cardiff and has released solo instrumental albums.

*Sources: imdb.com, siontrefor.com, filmmusicreporter.com.*

## On Fi1m (3)

- *Legends* (2026), Fi1m 74, Original Music Composer, Music — [page](https://film.one/tv/legends.md)
- *Toxic Town* (2025), Fi1m 77, Music, Original Music Composer — [page](https://film.one/tv/toxic-town.md)
- *Say Nothing* (2024), Fi1m 77, Music, Original Music Composer — [page](https://film.one/tv/say-nothing.md)

## Complete filmography (9)

Every credit, newest first. Titles without a page can be requested for review on the HTML page.

- *Effi o Blaenau* (2026), Original Music Composer
- *Legends* (2026), series, Original Music Composer — Fi1m 74, [page](https://film.one/tv/legends.md)
- *Love Me, Hold Me, Always* (2025), Music
- *Toxic Town* (2025), series, Original Music Composer — Fi1m 77, [page](https://film.one/tv/toxic-town.md)
- *London Recruits* (2024), Music
- *Say Nothing* (2024), series, Original Music Composer — Fi1m 77, [page](https://film.one/tv/say-nothing.md)
- *Sally Leapt Out of a Window Last Night* (2023), Music
- *Y Sŵn* (2023), Music
- *Rough Cut* (2022), series, Music

---
© Fi1m Ltd. Written by AI under a human editor; checked against sources before publication. Quote with attribution and a link to the canonical URL. Canonical: https://film.one/person/sion-trefor