Raised on a farm in Ponoka, Alberta, Shaun earned a Business Administration Diploma from Red Deer College and worked for a time with the Alberta Treasury Branch. After a few hard working years on his family’s homestead where farming was “a way of life and not a job,” he decided to return to college and begin his paper chase for a law degree. It was then that a drama elective inspired him to change direction, and he ultimately earned a Bachelor of Fine Arts in the University of Alberta's acclaimed drama program. This background helped determine the course of his career: “Having grown up on the prairies has had a great influence on my work as an actor. I like to believe my approach is open and natural. I guess I’m a product of my environment. ”Following his graduation, Johnston co-founded Shadow Theatre in Edmonton and made his first professional forays in Alberta's thriving theatre scene. He made his feature film debut in Two Brothers, a Girl and a Gun (1993). The role won him an Alberta Film & Television Award for best actor. Shaun points to determined archetypal western heroes like Gary Cooper, John Wayne, and Jimmy Stewart as models for the kind of man he likes to portray on screen, someone who stands for traditional values like honesty and patient acceptance of what life has to offer. Shaun claims, “All roles are extremely demanding. It’s the nature of the actor’s commitment. But if you want to increase that challenge, play an historical character. Then you feel the eyes of the world on you”. Shaun played the real-life wagon train captain in September Dawn (2007) and Colonel Nelson Miles in the Emmy-winning film Bury My Heart at Wounded Knee (2007). For these works and his other credits, Shaun received in 2011 the prestigious David Billington Award from the Alberta Media Production Industries Association.