After numerous parts on Broadway, including the musical What Makes Sammy Run, Sidney Kingsley's Night Live, America Hurrah,, Newman went on to do TV and movies.

Earlier, Newman co-starred in his first film, the gangster potboiler Pretty Boy Floyd (1960), and he made his breakthrough with his first starring role in The Lawyer (1970).

Newman is perhaps best known for his starring role as Kowalski in the 1971 cult film, Vanishing Point, about an existential journey across the western United States by a car transport driver delivering a white Dodge Challenger from Denver, Colorado to San Francisco, California.

In 1974, Petrocelli, a TV series created around the character Newman first played in The Lawyer, debuted on NBC and ran two seasons.

After Petrocelli, Newman starred in the film City on Fire with Henry Fonda and Ava Gardner, then in Disney's Amy.

Newman's success with the TV movie Night Games, based on the 1970 movie The Lawyer, led to the TV series Petrocelli, starring Newman as a lawyer who lives and works in the fictional town of San Remo, Arizona (filmed in Tucson, Arizona).