Wallace died on Saturday evening with his family by his side at Waveny Care Center in New Canaan, Connecticut, where he spent the past few years, CBS said in a statement and on its Sunday morning news broadcast.
"His extraordinary contribution as a broadcaster is immeasurable and he has been a force within the television industry throughout its existence. His loss will be felt by all of us at CBS," Leslie Moonves, president and CEO of CBS Corporation, said in the statement.
Wallace left his full-time role at "60 Minutes" in 2006 after 38 years and was given the title correspondent emeritus and a part-time contributor role. His last interview was with Roger Clemens, the star baseball pitcher accused of steroid use, in 2008.
A special "60 Minutes" program dedicated to Wallace will be aired April 15.
Just about anyone who made news during the past six decades - in the United States, but often abroad too - had to submit to a grilling by Wallace.
As a part-time correspondent, his most notable interview was with Mahmoud Ahmadinejad, president of Iran. It took place 27 years after his sit-down with that country's Ayatollah Khomeini, and earned Wallace his 21st Emmy.
In almost 40 years on "60 Minutes," the ground-breaking investigative journalism program, he worked on some 800 reports and developed a relentless on-air style that was often more interrogation than interview.
Wallace also drew criticism for his go-for-the-throat style and the theatrics that sometimes accompanied it. He also became caught up in a $120 million libel suit that resulted in no judgment against him or CBS but triggered a case of depression that led him to attempt suicide.
'FORGIVE ME FOR ASKING...'
Wallace interviewed every U.S. president since John F. Kennedy - with the exception of George W. Bush - and dozens of other world leaders like Yasser Arafat, Ayatollah Khomeini and Deng Xiaoping.
Other interview subjects included everyone from Malcolm X to Janis Joplin, Martin Luther King Jr., Johnny Carson, Vladimir Horowitz and Playboy founder Hugh Hefner.
When Wallace prefaced a question with "Forgive me for asking ..." or responded to a dubious answer with "Oh, come on," "60 Minutes" viewers knew he was about to get tough. His sometimes-abrasive manner resulted in the nickname "Mike Malice," and some viewers will always remember him as the man who made diva Barbra Streisand cry on camera.
In a 2006 retrospective of his "60 Minutes" career, Wallace summed up his interviewing technique as: "Let's ask the questions that might be on the minds of the people looking in ... 'If I were there in that chair where Wallace is, here's what I would want to know.'"
He was more succinct in a 2005 interview with The Boston Globe when he said: "I determined when I started back in 1956 ... there's no such thing as an indiscreet question."
Myron Leon Wallace was born in Brookline, Massachusetts, on May 9, 1918. He began calling himself Mike because he thought it was more manly than Myron. After graduating from the University of Michigan in 1939, he worked as a radio newswriter in Chicago and also on radio quiz shows, talk shows, a soap opera and serials like "The Green Hornet." He also acted on television and Broadway before joining CBS's radio department.
In 1955 Wallace found his calling with a television show called "Nightbeat," which featured Wallace asking pointed questions of writers, gangsters, artists and movie stars in front of a stark black backdrop.
'NASTY QUESTIONS, ABRASIVE QUESTIONS'
"We were doing the kind of show that had never been done before," Wallace said. "Nasty questions, abrasive questions, confrontational questions."
He returned to CBS in the early 1960s and was onboard "60 Minutes" for its September 24, 1968, debut. The show broke new ground in broadcast journalism with its surprise interviews, undercover reporters, hidden cameras and one-way mirrors.
One report for CBS sent Wallace into a personal tailspin. He worked on a 1982 CBS documentary that claimed the U.S. military conspired to misstate the strength of the enemy during the Vietnam War, which led to a $120 million libel suit from Gen. William Westmoreland.
The suit was dropped during the trial, CBS apologized and no money changed hands, but Wallace was traumatized by the accusations, which contributed to his depression.
Wallace's depression grew so severe he tried to kill himself with a drug overdose in 1984. He was saved by his wife, Mary.
Wallace often spoke about his recovery from depression and said the years after his suicide attempt were some of the most productive of his life.
Wallace, who was married four times, had a daughter, Pauline, and son, Chris, also a television journalist. Another son, Peter, died in a mountain-climbing accident in 1962.
(This version of the story has been corrected to fix the number of Emmys from 20 to 21)
(Reporting by Barbara Goldberg; Editing by Bill Trott and Frances Kerry)