Sienna Guillory is the daughter of Isaac Guillory, an American folk guitarist, and Tina Thompson, an English model. Her parents, being ardent advocates of artistic expression, encouraged her to explore her creative side from a young age, which ultimately led to her decision to pursue a career in acting. She received her education at Gresham's School, a prestigious institution located in Holt, Norfolk, England, where she honed her acting skills by appearing in various school plays.
Guillory's big break in the acting world came when she was just 16 years old, with a role in the TV movie "Riders" in 1993. To supplement her burgeoning acting career, she also ventured into modeling, appearing in campaigns for renowned fashion brands such as Armani and Dolce & Gabbana, as well as gracing the covers of numerous magazines. As her acting career continued to flourish, she landed roles in various TV shows and films, including "The Time Machine" in 2002, "Love Actually" in 2003, and the popular "Resident Evil" film series.