Sienna Guillory is an English actress and former model best known for playing the title role in the television miniseries Helen of Troy, for her role as Jill Valentine in the science fiction action horror films Resident Evil: Apocalypse, Resident Evil: Afterlife and Resident Evil: Retribution; as elf princess Arya Dröttningu in fantasy-adventure film Eragon.
Guillory is the daughter of American folk guitarist Isaac Guillory and Tina Thompson, an English model. Guillory's parents encouraged her to express herself artistically as she was growing up and this lead to her decision to become an actor.
She was educated at Gresham's School, Holt, Norfolk, England and appeared in school plays.
Her acting break came when she was 16, and was cast in the TV movie Riders (1993). To support her acting career, Guillory also took up modeling and appeared in campaigns for such high profile companies as Armani and Dolce & Gabbana, as well as gracing many magazine covers.
Further acting success followed in TV and films. Projects include The Time Machine (2002), Love Actually (2003) and the Resident Evil film series. She also appeared in the third season of the crime drama television series Luther.