Lear, one of the most influential people in television, died at his Los Angeles home of natural causes, Variety reported on Wednesday, citing his publicist.
Lear, who won six Emmy awards for his work in television, was known for his campaigning for progressive causes and worked well into his 90s.
In 2017, he rebooted his 1970s TV series One Day at a Time to focus on a Cuban American family, and in 2020 he earned his sixth Emmy for a live special broadcast of All in the Family and Good Times.
In February 2021, Lear received the Carol Burnett Award, a lifetime achievement award, at the Golden Globe Awards ceremony for his contributions to television.
In addition to All in the Family and Maude, Lear dominated US TV screens in the 1970s and '80s with the situation-comedy shows Sanford and Son, The Jeffersons and the soap-opera spoof Mary Hartman, Mary Hartman.
At one point in the 1970s Lear had eight shows on the air with an estimated 120 million viewers, Time magazine said.
By drawing material from social themes of the time, Lear's shows made network executives nervous because they had a depth and air of controversy.
"For him to say that he didn't have an impact on not only television but society is... a little too humble," said Rob Reiner, who had a co-starring role on All in the Family before becoming a film director.
Lear and production partner Bud Yorkin put All in the Family on the air in January 1971 and the show would go on to win four Emmys for best comedy in its nine seasons.
It was based on British show Til Death Do Us Part and gave US television one of its most memorable and controversial characters - Archie Bunker.
Carroll O'Connor portrayed Archie as a crude, loud, blue-collar New Yorker who spouted racist, homophobic and anti-Semitic comments.
He was cast against a scatter-brained wife he called "Dingbat," a progressive daughter and an even more progressive son-in-law he referred to as "Meathead" and played by Reiner.
All in the Family was the top-rated show on US television for five straight years, according to CBS, and TV Guide ranked it fourth on its list of television's all-time greatest shows.
Born on July 27, 1922 in New Haven, Connecticut, Norman Milton Lear's most lasting creation was partly based on fact.
Many of the harsh words that came out of Archie's mouth had first been spoken by Lear's own father, Herman Lear, who went to prison for selling fake bonds, and frequently told his wife to "stifle" herself and called his son "the laziest white kid I ever saw".
"I grew up in a family that lived at the top of its lungs and the ends of its nerves," Lear told Esquire magazine.
Some critics said the Archie Bunker character put a laughing face on bigotry but Lear said it only pointed to the complexity of humanity.
A year after All in the Family started, Lear aired Maude, a spin-off that starred Bea Arthur as Archie's acerbic sister-in-law and political opposite.
As with Bunker, the character was like none previously seen on US television.
Maude was on her fourth husband, protested marijuana laws and had an abortion before the US Supreme Court legalised the procedure.
Her husband battled alcoholism, had two nervous breakdowns and attempted to take his own life.
Lear, who grew up in Connecticut, dropped out of college in World War II to join the US army and flew 52 combat missions.
He went to Los Angeles in 1950 with the intention of being a publicist but began writing for TV stars such as Danny Thomas, Jerry Lewis, Dean Martin and Andy Williams.
