Sienna is the daughter of the late Isaac Guillory
, an American musician born at the Guantanamo Naval Base in Cuba, and his first wife, Tina Guillory
, from Norfolk, England. Isaac settled in the U.K. during the 1970s and had two daughters with Tina (Sienna and Jace), but the Guillorys separated when Sienna was in her teens. Isaac then married another Englishwoman, Victoria McMillan from Newcastle, where they settled and had two more children, Eleanor (Ellie, born 1994) and Easton Jacob (born 1998). Isaac died of cancer in December, 2000, at the age of 53. While her father was starting a new family in the North of England, Sienna stayed with her mother, Tina, who has a farmhouse near Wells-next-the-Sea in Norfolk where she designs and manufactures country clothes.
While still at Gresham's School, Holt
, Sienna was offered the part of Fenella in the movie Riders
(1993). She later trained for a career in acting at the New World School of the Arts
and at the Paris Conservatoire
. Later in the 1990s she became a model, working for Dolce & Gabbana, Paul Smith, Hugo Boss, Burberry, and Armani, and in 2000, readers of Esquire
magazine voted her the title of Britain's Most Eligible Woman
Nearly all of Sienna's screen work is in movies, so only a few credits show up at TV Rage. One of her best parts to date was in John Kent Harrison's blockbuster movie Helen of Troy
(2003), in which she played the title role.
Sienna lived with Nick Moran
from 1996 to 2000, then married the English-born actor Enzo Cilenti