Root was born in Sarasota, Florida, on November 17, 1951, the son of Leona Estelle and Rolland Clair Root, a project superintendent and site manager on major civil engineering projects throughout the US and Mexico. Root has likened his childhood to that of an Army brat, as his family frequently relocated while his father finished each construction project.
Root graduated from Vero Beach High School in Vero Beach, Florida. He received his Associate of Arts degree from the University of Florida and trained in the Bachelor in Fine Arts (BFA) acting program. The university recognized him as one of its distinguished alumni in 2008. Subsequently he was granted a BFA after completion of his final semester based on the quality and character of his acting career, having left college to pursue Broadway theater in his final semester.