Thaddea Graham

Thaddea Graham (born 29 March 1997)^[1] is a Northern Irish actress. She is known for her roles in the Sky One series Curfew (2019), the Netflix series The Letter for the King (2020), The Irregulars (2021) and Sex Education (2023), and the BBC series Us (2020), Doctor Who: Flux (2021) and Wreck (2022).

Thaddea Graham
Born	(1997-03-29) 29 March 1997 (age 28) China
Education	Arts Educational Schools (BA)
Occupation	Actress
Years active	2014–present

Graham appeared on the 2023 Screen International Rising Stars Ireland list.^[2]

Early life and education

Graham was adopted from an orphanage in Changsha, China at one year old and was raised in County Down.^[3] She was one of the first international adoptees in Northern Ireland.^[4] She attended Killinchy Primary School in Killinchy and later Bloomfield Collegiate School in Ballyhackamore.^[5][6] She trained with Arts Educational School in London, graduating with a Bachelor of Arts in Acting in 2018.^[7]

Career

Graham made her television debut with a recurring role in season 3 of The Sparticle Mystery. In December 2018,^[8] she landed her first major role as Iona in the 2020 Netflix fantasy series The Letter for the King, an adaptation of the classic Dutch book by Tonke Dragt.^[9][10] The following December, she was cast as Bea in the 2021 Sherlock Holmes spinoff The Irregulars, also on Netflix.^[11] In the meantime, she played Hanmei Collins in the Sky One action series Curfew, and Kat in the BBC One comedy-drama miniseries Us.^[12][13] She joined the cast of Doctor Who for its thirteenth series (known as Doctor Who: Flux) as Bel, making her debut in "Chapter Three: Once, Upon Time".^[14][15]

In 2022, Graham was in the main cast of the Virgin Media One and ITV crime drama Redemption as Siobhán Wilson and began starring as Vivian Lim opposite Oscar Kennedy and Jack Rowan in the BBC Three horror comedy Wreck. She joined the cast of the Netflix comedy-drama Sex Education for its fourth season playing the character "O".

In 2024, Graham was announced as part of the cast of Margot's Got Money Troubles created by David E. Kelley.^[16]

Filmography

Film

Year	Title	Role	Notes
2014	Painkiller		Short film
2021	VHS	Lea	Short film
2022	Ballywalter	Frances
2025	Jay Kelly	TBA	Post-production[17]
2025	After the Hunt	TBA	Post-production

Television

Year	Title	Role	Notes
2015	The Sparticle Mystery	Lucie	Series 3; 3 episodes
	Dani's Castle	Atka	Series 3; Episode 8: "Groundbog Day"
2019	Curfew	Hanmei Collins	Main role; 7 episodes
2020	The Letter for the King	Iona	Main role; Episodes 1–6
	Us	Kat	Main role; Mini-series; Episodes 1–3
2021	The Irregulars	Bea	Main role; Episodes 1–8
	Doctor Who	Bel	Series 13; Episodes 3–6
2022	Redemption	Siobhán Wilson	Main role; Mini-series; Episodes 1–6
2022–2024	Wreck	Vivian Lim	Main role; Series 1 & 2; 12 episodes
2023	Sex Education	Sarah 'O' Owens	Main role; Series 4; Episodes 1–8
2024	DNA Journey	Herself - Narrator	Series 5; Episodes 1–3
	Bad Sisters	DI Una Houlihan	Series 2
TBA	Margo's Got Money Troubles	Susie	Upcoming miniseries

Video games

Year	Title	Role	Notes
2022	Sifu	Fighter (voice)
2023	Dead Island 2	Jessie (voice)

Stage

Year	Title	Role	Notes
2016	London Stories Made by Migrants		Battersea Arts Centre[18]