Janet Ruth Montgomery is an English film and TV actress from Bournemouth, Dorset, United Kingdom.
She is known for her role as Ames in the second season of Fox's Human Target, and also for her appearances in The Hills Run Red and Wrong Turn 3: Left for Dead, as well as her role as Eric Murphy's assistant Jennie in HBO's Entourage. She recently played protagonist Martina Garretti in the short-lived Made in Jersey. As of 2014, she stars as the lead character, Mary Sibley, in the WGN America series, Salem. Janet can also be seen playing the role of Olivia Maine on the NBC TV series This Is Us.