Stuart Johnson completed undergraduate studies on violin before discovering the allure of playing the viola. After further study and freelancing overseas on both instruments Stuart returned to Australia to join the Sydney Symphony Fellowship program as a violist and was offered a place at the Australian National Academy of Music in Melbourne.

Stuart relocated to Sydney in 2009 when he joined the Sydney Symphony Orchestra as a permanent member. He has also been Guest Principal Viola with the West Australian Symphony Orchestra, Tasmanian Symphony Orchestra, Opera Australia Orchestra, Queensland Symphony Orchestra, held a permanent position with the Melbourne Symphony Orchestra, and has performed in the section of the Australian Chamber Orchestra and Singapore Symphony Orchestra. 

Stuart is currently teaching at the Sydney Conservatorium, Sydney Conservatorium High School, Sydney Conservatorium Rising Stars program, as well as at the Australian National University.