The Carter Centre said its founder, who was the oldest living former US president, died peacefully at his home in Plains, the town where he was born in Georgia, on Sunday afternoon.
He was surrounded by his family, a statement said, adding: “He was 100, the longest-lived president in US history.”
Mr Carter, a Nobel Peace Prize winner, who was president between 1976 and 1981, is survived by his children Jack, Chip, Jeff, and Amy, 11 grandchildren, and 14 great-grandchildren.
His son Chip Carter said: “My father was a hero, not only to me but to everyone who believes in peace, human rights, and unselfish love.
“My brothers, sister, and I shared him with the rest of the world through these common beliefs. 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.”
In February last year it was revealed Mr Carter was receiving hospice care and would “spend his remaining time at home with his family”.
He had decided against “additional medical intervention” following a series of brief hospital stays, the Carter Centre said in a statement at the time.
Mr Carter, a Democrat, became the 39th US president when he defeated former president Gerald Ford in 1976.
The Georgia native served a single term as president and was defeated by Republican Ronald Reagan in 1980.
The final year of his administration was dominated by a hostage crisis in Iran, when 52 Americans were taken captive at the US embassy in November 1979.
On the day he left office, 20 January 1981, the hostages were released. Carter had continued negotiations behind the scenes, even after his election defeat.
In 2002 he was awarded the Nobel Peace Prize for his work to avoid conflict around the world.
Mr Carter conducted diplomatic missions into his 80s and was involved in building houses for the poor well into his 90s.
“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,” Mr Carter once said.
When his wife of 77 years, Rosalynn Carter, died aged 96, in November 2023, the former president went to the memorial service held in her honour in Atlanta, Georgia.
He wore a blue and white blanket which was embroidered with her face.
