The former peanut farmer lived longer than any president in history and celebrated his 100th birthday in October.
The Carter Center, which advocates for democracy and human rights around the world, said he died on Sunday afternoon at his home in Plains, Georgia.
The Democrat served as president from 1977 to 1981, a period beset by economic and diplomatic crises.
After leaving the White House with low approval ratings, his reputation was restored through humanitarian work which earned him the Nobel Peace Prize.
“My father was a hero, not only to me but to everyone who believes in peace, human rights, and unselfish love,” his son, Chip Carter, said in a statement.
“The world is our family because of the way he brought people together, and we thank you for honouring his memory by continuing to live these shared beliefs.”
Carter – who prior to becoming president was governor of Georgia, a lieutenant in the US navy and a farmer – is survived by his four children, 11 grandchildren and 14 great-grandchildren.
His wife, Rosalynn, who he was married to for 77 years, died in November 2023.
Since 2018 and the death of George HW Bush, he was the oldest surviving US president.
Carter stopped medical treatment for an undisclosed illness last year and instead began receiving hospice care at his home.
President Joe Biden and First Lady Jill Biden said the world had “lost an extraordinary leader, statesman and humanitarian”.
Describing him as “a dear friend” and “a man of principle, faith and humility”, they added: “He showed that we are a great nation because we are a good people – decent and honorable, courageous and compassionate, humble and strong.”
“The challenges Jimmy faced as president came at a pivotal time for our country and he did everything in his power to improve the lives of all Americans,” President-elect Donald Trump wrote on social media.
“For that, we all owe him a debt of gratitude.”
Carter’s presidency will be remembered for his struggles in dealing with acute economic problems and several foreign policy challenges, including the Iran hostage crisis, which ended with the deaths of eight Americans.
There was, however, a notable foreign policy triumph in the Middle East when he helped broker an accord between Egypt and Israel, signed at Camp David in the US in 1978.
But that seemed a distant memory two years later, when voters overwhelmingly chose Republican Ronald Reagan, who had portrayed the president as a weak leader unable to deal with inflation and interest rates at near record highs.
Carter lost the 1980 election by a landslide, winning only six US states plus Washington DC.
In the aftermath of such a heavy defeat, Carter was frequently held up by Republicans as an example of liberal ineptitude.
Meanwhile, many in his own party either ignored him or viewed his presidential shortcomings as evidence their brand of Democratic politics or policy was a better way.
Today many on the right still deride the Carter years but as the decades passed, his humanitarian efforts and simple lifestyle began to shape a new legacy for many Americans.
After leaving the White House, he became the first and only president to return full-time to the house he lived in before politics – a humble, two-bedroom ranch-style home.
He chose not to pursue the lucrative after-dinner speeches and publishing deals awaiting most former presidents, telling the Washington Post in 2018 that he never really wanted to be rich.
Instead, he spent his remaining years trying to address global problems of inequality and disease.
He also teamed up with Nelson Mandela to found The Elders, a group of global leaders who committed themselves to work on peace and human rights.
In accepting his Nobel prize in 2002 – only the third US president to receive it – he said: “The most serious and universal problem is the growing chasm between the richest and the poorest people on Earth.”
In a statement, former President Bill Clinton and wife Hillary Clinton said he “worked tirelessly for a better, fairer world”, noting his humanitarian, environmental and diplomatic efforts.
“Guided by faith, President Carter lived to serve others – until the very end,” they added.
Former President Barack Obama paid tribute to Carter’s “decency” and said “he taught all of us what it means to live a life of grace, dignity, justice, and service”.
Republican former President George W Bush, meanwhile, said Carter “dignified the office” and that “his efforts to leave behind a better world didn’t end with the presidency”.
President Biden said a state funeral would be held in Washington DC.
At least 124 people have been confirmed dead after a Jeju Air flight crashed while attempting to land at Muan International Airport early Sunday morning.
