William Newman's film career began with a significant role in Stuart Rosenberg's 1980 film "Brubaker", starring the renowned Robert Redford. This marked the start of a long and illustrious acting career, with Newman's next notable appearance being in the 1981 film "The Postman Always Rings Twice", opposite the iconic duo Jack Nicholson and Jessica Lange.
Throughout the 1980s, Newman continued to take on a wide range of roles, showcasing his versatility as a character actor. He appeared in the Stephen King horror film "Silver Bullet" (1985) alongside Gary Busey and Corey Haim, the drama "The Mosquito Coast" (1986) with Harrison Ford and River Phoenix, and the Chevy Chase comedy "Funny Farm" (1988). Additionally, Newman played a sheriff in the 1986 film "The Last Days of Frank and Jesse James" and appeared in George A. Romero's "Monkey Shines" (1988),further demonstrating his ability to adapt to various genres.
The 1990s saw Newman's work continue without slowing down. He appeared in the horror film "Leprechaun" (1993),the comedy "Mrs. Doubtfire" (1993),Stephen King's "The Stand" (1994) opposite Rob Lowe, the teen thriller "The Craft" (1996),and the television series "Touch" (1997) alongside Skeet Ulrich.
Since then, Newman has maintained a steady presence in film, while also becoming a familiar face on television. His notable TV roles include the 1991 episode "Mr. Chaney" of "Eerie, Indiana", "Picket Fences" (1992),and "My Name Is Earl" (2005).