Boyle made his film debut in a small role in "The Virgin President" (1968), but first attracted the attention of critics in "Paul Sills Story Theatre" on Broadway--in a cast that also included Valerie Harper--and for "Joe". Working mostly in films and TV since then, he has moved back and forth between the two media, sometimes in top-notch productions, occasionally in productions not worth his talents. Although he made his TV-movie debut in "The Man Who Could Talk to Kids" (ABC, 1973), he is more often recalled for his critically-acclaimed turn as Senator Joseph McCarthy in "Tail Gunner Joe" (NBC, 1977). Boyle was Sgt. Fatso Judson, the part originally played by Ernest Borgnine on the big screen, in the TV miniseries based on "From Here to Eternity" (NBC, 1979). He headlined his own short-lived sitcom "Joe Bash" (ABC, 1986). He subsequently appeared as David Dellinger in "Conspiracy: The Trial of the Chicago Seven" (HBO, 1987) and as John Poindexter in "Guts and Glory: The Rise and Fall of Oliver North" (CBS, 1989). He also has made occasional appearances on the NBC series "Midnight Caller" and delivered an eerie Emmy-winning portrayal of the clairvoyant Clyde Bruckman on an seminal episode of "The X-Files" (Fox, 1995).

Boyle's memorable screen appearances of the 1980s and 90s include the role of the gangster turning the mantle of the family over to Michael Keaton in "Johnny Dangerously" (1984) and his turn as Ox, Sandra Bullock's future father-in-law in the charming romantic comedy "While You Were Sleeping" (1995). He was featured with fellow "Young Frankenstein" co-star Marty Feldman in the comedy "In God We Trust" (1980), as well as the British comedian's final feature "Yellowbeard" (1983) and played Cornelius Vanderbilt in the historical drama "Walker" (1987). Boyle reteamed with Keaton in 1989's "The Dream Team", both playing mental patients who get separated from their therapist on an outing in New York City, followed by a comedic turn in "Honeymoon in Vegas" and a serious stint in "Malcom X" (both 1992). He had a memorable supporting role in 1994's "The Santa Clause" (and its 2002 sequel) and subsequently acted in such notable features as "The Shadow" (1994), "That Darn Cat" (1997) and "Species II" (1998). He played a an unfeeling businessman turned good guy in the 1998 remake "Dr. Dolittle", starring Eddie Murphy, and reteamed with Murphy for 2002's bomb "Pluto Nash", a gangster comedy set on the moon in 2087. The actor delivered on of his finest serious performances in the indie smash "Monster's Ball" (2001) in an uncompromising turn as Billy Bob Thornton's cruel, racist father.

With frequent appearances on the small screen in regular or recurring roles on series including "Flying Blind" (Fox, 1992-1993) and "Lois and Clark: The New Adventures of Superman" (ABC, 1994-1995), Boyle kept busy. He returned triumphantly to regular series television work as the title character's father Frank on the CBS sitcom "Everybody Loves Raymond" (1996-2005). Making a impressive comedic team with co-star Doris Roberts (as his wife Marie), Boyle showcased both his perfect one-liner delivery and his unique ability to make a crusty and often outlandishly eccentric character inherently likeable. A key player on the popular series, Boyle won many laughs as well as successive Emmy nominations from 1999-2004 for his efforts. Boyle suffered a mild stroke in 1990, but his output was hardly slowed and he recovered fully. He also bounced back quickly from a mild heart attack on the set of "Everybody Loves Raymond" in March 1999, returning to the series soon after heart surgery and remaining through to its finale.

During "Raymond's" run Boyle also starred as the father of real-life turncoat spy Robert Hansen (William Hurt) in the telepic adaptation of Norman Mailer's "Master Spy: The Robert Hanssen Story" (2002) and he had a supporting role in the comedy "Scooby Doo 2: Monsters Unleashed" (2004).