Donahue began as a local TV reporter in Ohio and launched a talk show on CBS affiliate WHIO in Dayton.
In 1967, he moved "The Phil Donahue Show" to NBC affiliate WLWD, and by 1970, it entered nationwide syndication as "Donahue."
"Donahue" ran for 26 years in syndication, produced at NBC's 30 Rockefeller Plaza, until its final show in September 1996.
The show became famous for its open-forum interview style, allowing audience members and callers to ask questions, a format later adopted by Oprah Winfrey and others.
Donahue highlighted unique topics, such as breakdancing, and introduced it to a national audience in 1983.
Donahue is survived by his wife, Marlo Thomas, his sister, children, grandchildren, and his beloved golden retriever, Charlie.
The statement was provided to ABC News by a representative of Donahue's wife of 44 years, Marlo Thomas.
Donahue died on Sunday night from an undisclosed illness, as confirmed by a family statement.