The sister of Kristin Scott Thomas, Serena grew up in Dorset, England, one of five children. Her father (a British naval pilot) was killed in a flying accident when she was very young. Her mother remarried, and her step father, also a British naval pilot, died in a similar accident.

She worked as a fashion model until taking on a role in a BBC production of The Green Man. Apart from modelling and acting, she has enjoyed an equestrian career on both sides of the Atlantic, foxhunting and competing in Three Day Events and Dressage competitions.

Serena married Scott Tepper in 1996. They have a daughter, Tallulah, born in 1997, but are now divorced.