Winfield had been an ill health, suffering from obesity most of his life and diabetes, said his agent, Michael Livingston.
A few years ago while attending a dog show in Denver, Winfield went into a diabetic coma and was hospitalized for three weeks. "I knew I was a diabetic, but didn't take it seriously," he said an interview last fall. "Now I do."
The tall, imposing Winfield was only the third African American to receive an Academy Award nomination for best actor when he was honored for his performance as Nathan Lee Morgan, the loving sharecropper father in the 1972 classic "Sounder." Marlon Brando won the best actor Oscar that year for "The Godfather."
Last year, Winfield had a cameo in the ABC remake of the period piece set in the South in the 1930s. It was to be his last film role.
Though "Sounder" catapulted Winfield to fame, he did not follow in the footsteps of Sidney Poitier to become a black superstar. Cast mainly in character roles, Winfield consistently worked in film, television and theater, receiving an Emmy in 1995 for his role as a federal judge on "Picket Fences." He had previously received Emmy nominations for his lauded performance as the Rev. Martin Luther King Jr. in the 1978 miniseries "King" and another in 1979 for "Roots: the Next Generation."
In a 1984 interview with The Times, Winfield said he had been "given a lot of prestige -- [as] a distinguished black actor -- but very little power. They give prestige out by the buckets, but they give power by the teaspoon, just enough to stroke your ego."
Paul Edward Winfield was born in Los Angeles on May 22, 1941. His mother, Lois Beatrice, was a union organizer in the garment industry; his stepfather, Clarence Winfield, was a construction worker.
Winfield once said that he was so precocious he was taken to see a psychiatrist when he was 3. "I wasn't a particularly disturbed child, but I wasn't a normal one either," he said.
He spent his early years in Portland, Ore. Movie theaters were still segregated, with blacks forced to sit in the balcony. In a 1973 Times interview, he recalled the impact the 1949 film "Home of the Brave," which starred African American actor James Edwards in a leading role, had on the black community of Portland.
"Suddenly a black actor was playing a major role, not just a servant or a chauffeur, and we weren't going to sit in the balcony anymore either," he said.
After the family moved to Watts, Winfield was bused to predominately white Manual Arts High School in Los Angeles. It was while attending Manual Arts that he met Reuben Plaskoff, the drama coach who encouraged him to act.
Winfield was subsequently named best actor two years in a row by the Southern California Speech and Drama Teachers Assn. Gifted at both violin and cello, he won a scholarship to Yale University.
But he accepted a scholarship in drama to the University of Oregon because, he said, he thought "college was scary enough without going to a rich one." He later attended several West Coast universities and left UCLA six credits short of his degree in 1964, when he was cast in a professional production of LeRoi Jones' "The Dutchman and the Toilet." Two years later, Columbia put him under contract.
Guest-starring roles soon followed on "Room 222" and "Julia," in which he played Diahann Carroll's boyfriend. He considered his role in "Julia" the only meaningful acting he had done until "Sounder.'
"Since I am not particularly pretty and I can't sing or dance, I started off in television with a lot of bit parts either as a black activist or some type of psychopathic heavy," he said.
His "Sounder" on-screen leading lady, Cicely Tyson, also became his off-screen paramour. The two lived together for 18 months. "I was extremely competitive," Winfield once said in explaining their parting. "I was hostile to the attention she was getting, even though it was due."
After he and Tyson broke up, he went through a series of bad relationships. In 1975, he moved to San Francisco, and a few years later reunited with Tyson for "King" and "A Hero Ain't Nothin' but a Sandwich." In 1978, People magazine described Winfield as "the most ubiquitous black TV/movie actor of the decade."
Moving back to Los Angeles in the 1980s, he appeared in such films as "Star Trek II: The Wrath of Khan" and starred on stage in works by Shakespeare, Ibsen and Chekhov. He starred opposite Denzel Washington in Ron Milner's play "Checkmates" in Los Angeles, and repeated his role in the 1988 Broadway production.
The 1990s began on a high note with a juicy role as a judge in the 1990 hit "Presumed Innocent." He appeared in Los Angeles opposite Carroll in "Love Letters" and won the Emmy for his guest-starring role on "Picket Fences."
Winfield admitted that he hit a dry spell in the 1990s. Then in 1998, he was offered to narrate the A&E crime documentary series "City Confidential."
Besides his acting career, Winfield also bred and showed black pug dogs for several decades until his diabetes forced him to stop. Never married, Winfield shared his Hollywood Hills home with seven pugs, each named after a Shakespearean character, and more than 600 ceramic and bronze pug figures.
He is survived by a sister, Patricia Wilson of Las Vegas. Funeral services are pending.