Phil Donahue, a pioneering US talk show host, has died at the age of 88.

Donahue's death in Manhattan on Sunday following a long illness was announced on NBC's Today Show, where he made frequent appearances from 1979 to 1988.

"The Phil Donahue Show," launched in 1967, was the first on daytime US television to feature audience participation.

It remained popular through the 1970s and into the 1980s, earning Donahue numerous Emmy Awards, and the format was adopted by future talk show hosts such as Oprah Winfrey.

The Donahue show was also notable for bringing conversations about controversial issues such as abortion, religion and sex to daytime television.

Donahue received the Presidential Medal of Freedom from President Joe Biden in May.

"He pioneered the live daytime talk show, holding a mirror up to America," the White House said.

"He interviewed everyone from our greatest stars to our forgotten neighbours, uniting us around the toughest issues of our time."

Donahue was married for 44 years to actress Marlo Thomas, the star of the 1960s sitcom "That Girl." (AFP)