Thaddea Graham (born 1997 or 1998) is a Northern Irish actress.
2018
She trained with Arts Educational School in London, graduating with a Bachelor of Arts in Acting in 2018.
Graham made her television debut with a recurring role in season 3 of The Sparticle Mystery.
In December 2018, 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.
The following December, she was cast as Bea in the 2021 Sherlock Holmes spinoff The Irregulars, also on Netflix.
In the meantime, she played Hanmei Collins in the Sky One action series Curfew, and Kat in the BBC One comedy-drama miniseries Us.
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.
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".
2019
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).
Graham appeared on the 2023 Screen International Rising Stars Ireland list.
Graham was adopted from an orphanage in Changsha, China at one year old and was raised in County Down.
She was one of the first international adoptees in Northern Ireland.
She attended Killinchy Primary School in Killinchy and later Bloomfield Collegiate School in Ballyhackamore.
