Malden died of natural causes surrounded by his family at his Brentwood home, they told the Academy of Motion Picture Arts & Sciences. He served as the academy's president from 1989-92.
CBS Radio news correspondent Sam Litzinger reports Malden was known for his bulbous nose, bullhorn voice and a certain gruffness he brought to more than six decades of acting roles.
"Karl lived a rich, full life," Academy president Sid Ganis said. "He has the greatest and most loving family; a career that has spanned the spectrum of the arts from theater to film and television, to some very famous commercial work."
While he tackled a variety of characters over the years, he was often seen in working-class garb or military uniform. His authenticity in grittier roles came naturally: He was the son of a Czech mother and a Serbian father, and worked for a time in the steel mills of Gary, Indiana, after dropping out of college.
Malden said he got his celebrated bulbous nose when he broke it a couple of times playing basketball or football, joking that he was "the only actor in Hollywood whose nose qualifies him for handicapped parking." He liked to say he had "an open-hearth face."
Malden won a supporting actor Oscar in 1951 for his role as Blanche DuBois' naive suitor Mitch in "A Streetcar Named Desire"
a role he also played on Broadway.
He was nominated again as best supporting actor in 1954 for his performance as Father Corrigan, a fearless, friend-of-the-workingman priest in "On the Waterfront." In both movies, he costarred with Marlon Brando.
"When you worked with him, he was the character," said Eva Marie Saint, who garnered a supporting actress Oscar for her role in "Waterfront." "He was the consummate actor and he loved acting. He was dear and smart. Whatever he did he enjoyed life."
Among Malden's more than 50 film credits were: "Patton," in which he played Gen. Omar Bradley, "Pollyanna," "Fear Strikes Out," "The Sting II," "Bombers B-52," "Cheyenne Autumn," and "All Fall Down."
One of his most controversial films was "Baby Doll" in 1956, in which he played a dullard husband whose child bride is exploited by a businessman. It was condemned by the Catholic Legion of Decency for what was termed its "carnal suggestiveness." The story was by "Streetcar" author Tennessee Williams.
Malden gained perhaps his greatest fame as Lt. Mike Stone in the 1970s television show "The Streets of San Francisco," in which Michael Douglas played the veteran detective's junior partner.
"Karl `The Mentor' Malden was a great actor, father and husband. I admired and loved him deeply," Douglas, who was in Europe, said through his publicist.
Douglas saluted Malden last month when he received the American Film Institute's Lifetime Achievement Award.
"It was Karl who, more than anyone, got me to understand that an actor is just one part of a whole team that makes a TV series or movie work," Douglas said in the upcoming July 19 airing of the event on TV Land.
In the '70s, Malden gained a lucrative 21-year sideline and a place in pop culture with his "Don't leave home without them" ads for American Express.
"The Streets of San Francisco" earned him five Emmy nominations. He won one for his role as a murder victim's father out to bring his former son-in-law to justice in the 1985 miniseries "Fatal Vision." He and Saint played husband and wife.
Malden played Barbra Streisand's stepfather in the 1987 film "Nuts;" Adm. Elmo Zumwalt Jr. in the 1988 TV film "My Father, My Son;" and Leon Klinghoffer, the cruise ship passenger murdered by terrorists in 1985, in the 1989 TV film "The Hijacking of the Achille Lauro."
He acted sparingly in recent years, appearing in 2000 in a small role on TV's "The West Wing."
In 2004, Malden received the Screen Actors Guild's Lifetime Achievement Award, telling the group in his acceptance speech that "this is the peak for me."
Malden first gained prominence on Broadway in the late 1930s, making his debut in "Golden Boy" by Clifford Odets. It was during this time that he met Elia Kazan, who later was to direct him in "Streetcar" and "Waterfront."
He steadily gained more prominent roles, with time out for service in the Army in World War II (and a role in an Army show, "Winged Victory.")
"A Streetcar Named Desire" opened on Broadway in 1947 and went on to win the Pulitzer Prize and New York Drama Critics Circle awards. Brando's breakthrough performance might have gotten most of the attention, but Malden did not want for praise. Once critic called him "one of the ablest young actors extant."
Among his other stage appearances were "Key Largo," "Winged Victory," Arthur Miller's "All My Sons," "The Desperate Hours," and "The Egghead."
Malden was known for his meticulous preparation, studying a script carefully long before he stepped into his role.
"I not only figure out my own interpretation of the role, but try to guess other approaches that the director might like. I prepare them, too," he said in a 1962 Associated Press interview. "That way, I can switch in the middle of a scene with no sweat."
"There's no such thing as an easy job, not if you do it right," he added.
He was born Mladen Sekulovich in Chicago on March 22, 1912. Malden regretted that in order to become an actor he had to change his name. He insisted that Fred Gwynne's character in "On the Waterfront" be named Sekulovich to honor his heritage.
The family moved to Gary, Indiana, when he was small. He quit his steel job 1934 to study acting at Chicago's Goodman Theatre "because I wasn't getting anywhere in the mills," he recalled.
"When I told my father, he said, `Are you crazy? You want to give up a good job in the middle of the Depression?' Thank god for my mother. She said to give it a try."
In 2005, the U.S. Postal Service honored Malden by naming the post office in Brentwood to honor his achievement in film and his contributions to the Citizens' Stamp Advisory Committee, which meets to discuss ideas for stamp designs.
Malden helped create the "Legends of Hollywood" stamp series that has featured Marilyn Monroe, James Dean and Gary Cooper, and another celebrating Hollywood's behind-the-scenes workers.
"As a kid, all the letters that would come from the old country, he would see the stamps and they always intrigued him," said David Failor, executive director of stamp services for the Postal Service. "He was such a regular guy."
Malden and his wife, Mona, a fellow acting student at the Goodman, had one of Hollywood's longest marriages, having celebrated their 70th anniversary in December.
"That was sort of the last goodbye," said Saint, who attended a party in the couple's honor. "His wish was, `After I die, I don't want you to do anything but have a party.' So another party is coming up."
Besides his wife, Malden is survived by daughters Mila and Cara, his sons-in-law, three granddaughters, and four great grandchildren.