Juliet van Kampen Rylance (born 26 July 1979) is an English actress and producer, known for her roles in The Knick, McMafia and Perry Mason.

[4] Her first major role upon leaving RADA was as Medea in Neil LaBute's Bash: Latter-Day Plays at the Union Theatre in London.

She portrayed British writer Mary Sidney in I Am Shakespeare, written by her step-father Mark Rylance and directed by Matthew Warchus at the Chichester Festival Theatre and its UK tour.

That same year, along with two of her contemporaries, David Sturzaker and director Tamara Harvey, she started her own production company, Theater of Memory.

In 2013 she appeared in and produced the film Days and Nights, based on the Anton Chekov play The Seagull, and written and directed by her husband.