Previous to this post Johnston served as the 27th president of Iowa Wesleyan College for six years, and as a lower level administrator at Bethany College in Bethany, West Virginia, Davis & Elkins College in West Virginia, West Virginia Wesleyan College, and Ashland University in Ohio.
Before taking on this role, Johnston served as the president of Iowa Wesleyan College for six years and held various administrative positions at other colleges, including Bethany College, Davis & Elkins College, West Virginia Wesleyan College, and Ashland University.