Phil Donahue, a pioneering daytime television talk show host, has died, his family said. He was 88.

Family members told Today that the television star died Sunday night surrounded by loved ones after a long illness of unknown cause, including his wife, actress Marlo Thomas, whom he married in 1980, three years after they met at a taping of his show “Donahue.”

The Donahue family asked fans who wanted to donate in his name to St. Jude Children’s Research Hospital or to the scholarship fund Donahue established at the University of Notre Dame, where he graduated in 1957.

The Cleveland native was a pioneer in television, credited with introducing a format in which active viewer involvement was essential to the program. He was on the air for nearly 30 years before leaving “Donahue” in 1996.

Her TV colleague Oprah Winfrey once praised Donahue for “opening the door wide enough for me to walk through,” and said her career might never have happened without the vision of her 20-time Emmy Award winner.

Talk show hosts such as Winfrey, Morton Downey Jr. and Geraldo Rivera followed in his footsteps in the late 1980s, followed by the likes of Jenny Jones, Jerry Springer and Maury Povich.

Rivera posted on social media that he was deeply saddened by Donahue’s death, calling him “a hero, a talk show pioneer who inspired me to try my hand at the genre he invented.”

When President Joe Biden awarded Donahue the Presidential Medal of Freedom last May, the White House called his talk show “one of the most influential television programs of its time.”

Donahue briefly returned to television in 2002, with a current affairs program for MSNBC that ran for less than a year.

That same year, TV Guide ranked “Donahue” the 29th best television show of all time, in a list topped by “Seinfeld” and also including “I Love Lucy,” “The Honeymooners,” “Saturday Night Live” and “The Cosby Show.”

His career in radio and television began in 1957 with a job as a production assistant at KYW in Cleveland. He soon found his way to the microphone. In 1967, he started “The Phil Donahue Show” on a local station in Dayton. That show went national in 1970 and began taping in Chicago. Donahue came to New York City in 1984 when his show moved to 30 Rockefeller Center, where he also contributed to the “Today” show from 1979 to 1988.

He recorded nearly 7,000 one-hour episodes of his talk show before airing his farewell show on September 13, 1996.

On Monday morning, numerous condolences poured in following the news of Donahue’s death.

“One of the true groundbreaking icons of American television,” host Piers Morgan posted to X. “Such a smart, interesting man.”

ABC News anchor Deborah Roberts remembered Donahue as a catalyst for her work.

“Like so many journalists, he has inspired me throughout my career,” she posted on social media. “What a life!”

Donahue was inducted into the Television Hall of Fame almost immediately after leaving the grind of television. He credited his parents and wife for his success, and especially thanked his children for their receptiveness to the programs he brought to the screen.

“My children, Michael, Kevin, Dan, Jim and Mary Rose, have handled the stress of having a celebrity father who is known for hosting transvestites, people who kill their mothers, people who kill their fathers, people who are their own grandfathers, their own uncles, very, very well, and they are proud of me to this day and call me all the time,” he joked during his induction ceremony in 2003.”

The Gay & Lesbian Alliance Against Defamation (GLAAD) honored Donahue at its first GLAAD Media Awards in 1990. He was honored again by GLAAD in 1993, receiving special recognition for his groundbreaking reporting on gay, lesbian and transgender issues.