His shows have generally focused on issues that often divide liberals and conservatives in the United States, such as abortion, consumer protection (his most frequent guest was Ralph Nader, for whom he campaigned in 2000), civil rights and war protests. Donahue also hosted a talk show on MSNBC from 2002 – 2003.
Donahue was born into a lower-middle-class, churchgoing Irish Catholic family; his father was a furniture sales clerk and his mother a department store shoe clerk. In 1949, he was in the graduating class of Our Lady Of Angels. In 1953, Donahue was a member of the first graduating class of St. Edward High School, an all-boys college prep Catholic high school run by the Brothers of Holy Cross in suburban Lakewood, Ohio. He graduated from the University of Notre Dame with a B.B.A. in 1957. A year later he married his first wife, Marge Cooney, who divorced him in 1975. There were five children from that marriage. He married his second (and present) wife, actress Marlo Thomas, in 1980. They have lived in Westport, Connecticut since 1986.
Donahue began his career in 1957 as a production assistant at KYW radio and television in Cleveland. He got a chance to become an announcer one day when the regular announcer failed to show up. After a brief stint as a bank check sorter in Albuquerque, New Mexico, he became program director for WABJ radio in Adrian, Michigan, soon after graduating. He moved on to become a stringer for the CBS Evening News and later, an anchor of the morning newscast at WHIO-TV in Dayton, Ohio, where his interviews with Jimmy Hoffa and Billie Sol Estes were picked up nationally. While in Dayton, Donahue also hosted Conversation Piece, a phone-in afternoon talk show from 1963 to 1967 on WHIO radio. There, among others, he interviewed civil rights activists (including Dr. Martin Luther King Jr., Malcolm X) and war dissenters.
In 1967, Donahue left the WHIO stations and moved his talk program to television with The Phil Donahue Show on WLWD (now WDTN), also in Dayton. Initially, the program was shown only on other stations owned by the Crosley Broadcasting Corporation (which would later take the name of its parent Avco Company), which also owned WLWD. But, in January 1970, The Phil Donahue Show entered nationwide syndication.
After a 29-year run—26 years in syndication—the final original episode of Donahue aired in May 1996, culminating what remains the longest continuous run of any syndicated talk show in U.S. television history.
While hosting his own program, Donahue also appeared on NBC's The Today Show as a contributor, from 1980 until 1982. From 1991 to 1994 he also co-hosted Pozner/Donahue, a weekly, issues-oriented roundtable program with Soviet journalist Vladimir Posner, which aired both on CNBC and in syndication.