Root studied acting and broadcasting at the University of Florida. While at school, he won a regional audition for the National Shakespeare Company and left his studies to embark on a three-year tour of the U.S. and Canada, playing various roles in "Hamlet," "The Winter's Tale" and "Romeo and Juliet." Afterwards, Root settled in New York City, and following the traditional sojourn spent waiting tables he landed his first off-Broadway role in a revival of "Journey's End." He won his first Broadway role in "So Long on Lonely Street" in 1986, and the following year played Frank Lubey in the Tony Award-winning revival of Arthur Miller's "All My Sons." A starring role the same year in the touring production of "Driving Miss Daisy" opposite Julie Harris brought Root to Los Angeles.
The actor earned two film credits each year in his first four years in Southern California, playing roles in "Crocodile Dundee II," "Monkey Shines," "Black Rain," "Ghost" and others before landing a string of telefilm roles and series guest parts. His TV movie credits include "The Betty Broderick Story" and "Class of '61" (both 1992). He also had recurring roles in "From the Earth to the Moon," "Sweet Justice," and "L.A. Law." He was nominated for a Cable Ace award for Best Supporting Actor for his role in USA Network's "Road to Galveston" (1996).
Root's first starring role in a TV series came in 1991 with Stephen King's "The Golden Years." He won the role of R.O. Moon in the short-lived series "Harts of the West" in 1993 before being asked to play Jimmy James in "NewsRadio," which remains the only sitcom in history to have named ten of its episodes after Led Zeppelin albums. Regarding his eccentric, much-loved billionaire character, Root says he found his inspiration close to home: "My father, a construction supervisor, just knew how to get things done in a simple, to-the-point manner."
Root's first experience in animation voiceover came in 1997 when he created the character of Bill Dauterive, Hank Hill's lonely neighbor on Mike Judge's hit FOX series "King of the Hill." The character once neatly summed up his state of being with the now-immortal phrase "I'm so depressed I can't even blink." Along with his additional roles as Strickland and Topsy on "King of the Hill," Root's other animation credits include Dr. Donovan on "Big Guy and Rusty the Boy Robot," Sheriff on "Buzz Lightyear of Star Command" and Cat Man in "Justice League." Last year, Root also gave a voice to the ursine Zeb Zoober in Disney's "The Country Bears" and bellicose rhino Frank in "Ice Age."
Root's film credits include Gary Murray in "Buffy the Vampire Slayer" (1992), white-collar nebbish Milton Waddams in Mike Judge's "Office Space" (1999), NorthAm Robotics head Dennis Mansky in "Bicentennial Man" (1999), and blind station manager Lund in the Coen brothers' "O Brother, Where Art Thou?" (2000). Later this year Root will appear in director Kevin Smith's latest Miramax feature "Jersey Girl."
The actor lives in Los Angeles. He passes his off hours spending time with his family and improving his golf game.