She first appeared in the 1988 version of The Hound of the Baskervilles as Beryl Stapleton. A year later she appeared in the mini-series Mother Love.
In 2011 she co-produced the feature film City Slacker, written by her husband, Michael Müller. In the film, Gillies plays Amanda, a high-powered businesswoman who suddenly needs to conceive a baby when her frozen eggs are destroyed.
Gillies also produced The Beat Beneath My Feet, about a former rock God, played by Luke Perry, who is discovered living in a flat in South London. The film also stars Nicholas Galitzine. Production was completed in 2014
