Beginning in 1968, as one of the first hosts of the enduringly popular news show, he circled the globe, displaying his charm and wit and asking sometimes barbed, always penetrating questions of kings and presidents, business magnates and bureaucrats, entertainers and cultural personalities.
Of the roughly 800 pieces the pioneering correspondent did for "60 Minutes," two stood out the most for him, Wallace told the Associated Press in 2006.
One showed his tender side as Wallace persuaded piano virtuoso Vladimir Horowitz to pound out "Stars and Stripes Forever" in 1977. The other, in 1979, showed Wallace's tough side as he became the first Western reporter to interview Iran's Ayatollah Ruhollah Khomeini after more than 50 Americans were taken hostage in Tehran. To Khomeini's face, Wallace quoted Egyptian President Anwar Sadat as calling him a lunatic.
"I figured what was he going to do, take me as a hostage?" Wallace said. "The translator looked at me as if I were a lunatic."
When he interviewed Nation of Islam minister Louis Farrakhan in 2000, Wallace set an incendiary tone: "You don't trust the media; you've said so. You don't trust whites; you've said so. You don't trust Jews; you've said so. Well, here I am."
"So what?" Farrakhan responded.
Wallace so specialized in the hard-hitting search for skulduggery that beer magnate Joseph Coors once quipped: "The four most frightening words in the English language are 'Mike Wallace is here.'"
The comment was adapted into an advertisement, and Wallace displayed a framed copy in his office.
Barbara Walters, a formidable interviewer and a competitor at ABC, offered a telling compliment on the 1997 special "Mike Wallace Remembers": "The best interviewer in all of television — past, present and probably future — is Mike Wallace."
The veteran broadcaster stepped down as a full-time correspondent in 2006, when he was 88. He made occasional appearances after that, culminating with his final interview in January 2008, with baseball pitcher Roger Clemens.
"60 Minutes" creator Don Hewitt — who died in 2009 — told People magazine in 2006: "If they were allowed to put plaques up at CBS for the three journalists who would stand out, they would be Edward R. Murrow, Walter Cronkite and Mike Wallace."
Jeff Fager, the show's current executive producer, told The Times in 2006, "I don't think there would be a '60 Minutes' if Don hadn't found Mike. Mike was never afraid to say what he thought."
Wallace's unapologetic style made for splashy, often emotional interviews — and the occasional dust-up.
The controversy that most affected Wallace grew out of a 1982 "CBS Reports" documentary he narrated on the Vietnam War. The report stated that Gen. William Westmoreland had inflated enemy casualty figures to maintain support for the unpopular war. Westmoreland sued CBS and Wallace for $120 million but dropped the suit months into the trial.
"The Westmoreland affair, professionally and personally, was one of the most difficult times of my life," Wallace told the Chicago Tribune in 1989. "It was just devastatingly difficult because my integrity was put to question, and as a reporter, that's the single most important thing you've got."
The 1984 trial triggered Wallace's first bout of clinical depression, and he tried to kill himself by swallowing sleeping pills. He publicly acknowledged the suicide attempt during a "60 Minutes" tribute to him in 2006.
With the support of Mary Yates, a longtime friend who would become his fourth wife, Wallace got the help he needed to treat his depression. He began seeing a psychiatrist and taking antidepressants, Wallace wrote in his 2005 memoir, "Between You and Me."