Chip Carter, the son of the former president, said the elder Carter died around 3.40pm local time at his home in Plains, Georgia, where he had been receiving hospice care.
It was where he and his wife, Rosalynn, who died at 96 in November 2023, spent most of their lives, the Carter Centre said.
Carter won the presidency in the wake of the Watergate scandal and the Vietnam war and became known as a global humanitarian after leaving office.
Chip said that his father “was a hero, not only to me but to everyone who believes in peace, human rights, and unselfish love.”
He added: “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.”
Our founder, former U.S. President Jimmy Carter, passed away this afternoon in Plains, Georgia. pic.twitter.com/aqYmcE9tXi
“Today, America and the world lost an extraordinary leader, statesman and humanitarian,” he said.
“Over six decades, we had the honour of calling Jimmy Carter a dear friend. But, what’s extraordinary about Jimmy Carter though is that millions of people throughout America and the world who never met him thought of him as a dear friend as well.
“With his compassion and moral clarity, he worked to eradicate disease, forge peace, advance civil rights and human rights, promote free and fair elections, house the homeless, and always advocate for the least among us. He saved, lifted and changed the lives of people all across the globe.
“He was a man of great character and courage, hope and optimism.”
Known for his work ethic, the 39th president continued to conduct diplomatic missions into his 80s and built houses for the poor well into his 90s.
A peanut farmer by upbringing who was deeply committed to his religious faith, Carter once said: “My faith demands — this is not optional — my faith demands that I do whatever I can, wherever I am, whenever I can, for as long as I can, with whatever I have to try to make a difference.”
A moderate Democrat, Carter entered the 1976 presidential race against Republican Gerald Ford as a little-known Georgia governor with a background in engineering.
He was swept into the White House off the back of a no-frills campaign that depended on public financing and a promise not to deceive the American people that resonated following Richard Nixon’s ignominious departure from office in 1974.
Carter governed amid Cold War pressures, turbulent oil markets and social upheaval over racism, women’s rights and America’s role on the global stage.
He was the first president since Thomas Jefferson under whom no blood was shed in a war.
His most notable achievement in office was a Middle East peace deal that he brokered by keeping Egyptian President Anwar Sadat and Israeli Prime Minister Menachem Begin at the bargaining table for 13 days in 1978.
That Camp David experience inspired the post-presidential centre where Carter would establish so much of his legacy.
Yet his electoral coalition splintered under double-digit inflation queues for petrol and the 444-day hostage crisis in Iran triggered in the wake of the country’s 1979 revolution.
His bleakest hour came when eight Americans died in a failed hostage rescue in April 1980 in the lead-up to the election, helping to ensure his landslide defeat to Republican Ronald Reagan later that year.
Following his departure from office, the Carters founded the Carter Centre in 1982, positioning themselves as international peacemakers and champions of democracy, public health and human rights.
The centre’s achievements included easing nuclear tensions in North and South Korea, helping to avert a US invasion of Haiti and negotiating cease-fires in Bosnia and Sudan.
By 2022, the Carter Centre had declared at least 113 elections in Latin America, Asia and Africa to be free or fraudulent. Recently, the centre began monitoring US elections as well.
In 2002, Carter won the Nobel Peace Prize, with the committee citing his “untiring effort to find peaceful solutions to international conflicts, to advance democracy and human rights, and to promote economic and social development”.
In his later years, the former president spent his days in the same one-storey Plains house he had lived in before he became governor.
He regularly taught Sunday School lessons at Maranatha Baptist Church until his mobility declined and the coronavirus pandemic raged.
Those sessions drew visitors from around the world to the small sanctuary where Carter will receive his final send-off after a state funeral at Washington’s National Cathedral.
The New York Times reported he died after deciding nearly two years ago to forgo further medical care following a series of medical crises.
In 2010 he returned to the White House to greet President Barack Obama and discuss international affairs amid rising tensions on the Korean peninsula.
In 2015, he revealed he had cancer which had been diagnosed after he underwent surgery to remove a small mass in his liver.
Carter underwent immunotherapy and radiation therapy, before announcing in March the following year that he no longer needed any treatment.
Former first lady Rosalynn Carter, the closest adviser to Carter during his term as US president, died in November 2023. She had been living with dementia and suffering many months of declining health.
“Rosalynn was my equal partner in everything I ever accomplished,” Carter said in a statement following her death.
“She gave me wise guidance and encouragement when I needed it. As long as Rosalynn was in the world, I always knew somebody loved and supported me.”
United Kingdom Prime Minister Sir Keir Starmer said: “Motivated by his strong faith and values, President Carter redefined the post-presidency with a remarkable commitment to social justice and human rights at home and abroad.”
Starmer added that Carter “lived his values in the service of others to the very end”.
The Carter Centre said that the final arrangements for his funeral are still pending. The Carter family asked that donations be made to the Carter Centre in lieu of flowers.
The 39th US president is survived by his children - Jack, Chip, Jeff and Amy - as well as by 11 grandchildren and 14 great-grandchildren.
Trump, Clinton pay tribute to Carter
Donald Trump said Carter had done “everything in his power” to improve Americans’ lives.
“Those of us who have been fortunate to have served as president understand this is a very exclusive club, and only we can relate to the enormous responsibility of leading the greatest nation in history,” the President-elect wrote on social media.
“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,” he added.
“Melania and I are thinking warmly of the Carter family and their loved ones during this difficult time. We urge everyone to keep them in their hearts and prayers.”
Former President Bill Clinton paid tribute to Carter in a joint statement with Hillary Clinton, the former US Secretary of State and First Lady.
“Hillary and I mourn the passing of President Jimmy Carter and give thanks for his long, good life,” he said. “Guided by his faith, President Carter lived to serve others – until the very end.”