Thaddea Graham

Thaddea Graham is a Northern Irish actress who has appeared in numerous television series and film projects. She gained recognition for her performances across major network and streaming productions, establishing a prominent presence in television drama, comedy, and fantasy programming.

Graham was born in Changsha, China, on 29 March 1997. Adopted from an orphanage at the age of one, she grew up in County Down as one of Northern Ireland's earliest international adoptees. She received her early education at Killinchy Primary School and Bloomfield Collegiate School. She later moved to London to pursue formal dramatic training at the Arts Educational School, earning a Bachelor of Arts degree in Acting in 2018.

Her early professional screen work included a recurring television role in the third season of The Sparticle Mystery. Her career advanced rapidly following her drama school graduation, leading to recurring and guest parts in high-profile television projects. She played Hanmei Collins in the Sky One action series Curfew and portrayed Kat in the BBC One comedy-drama miniseries Us.

In late 2018, Graham secured a major breakthrough when she was cast as Iona in the 2020 Netflix fantasy adaptation The Letter for the King, based on Tonke Dragt's classic novel. Soon after, she landed the leading role of Bea in the 2021 Netflix Sherlock Holmes spinoff series The Irregulars. That same year, she entered the cast of Doctor Who during its thirteenth series, Doctor Who: Flux, portraying the character Bel.

Graham continued to secure leading television roles in subsequent years. In 2022, she featured as Siobhán Wilson in the crime drama Redemption and began playing Vivian Lim in the BBC Three horror comedy series Wreck. She subsequently joined the fourth season of the Netflix series Sex Education, portraying a character named O. Her screen work expanded to include the Apple TV+ series Bad Sisters and the film After the Hunt.

Her industry recognitions include being named to the Screen International Rising Stars Ireland list in 2023. Graham's ongoing projects include roles in Apple TV+'s Margo's Got Money Troubles.