Rosalynn Carter passed away peacefully with family by her side at her home in Plains, Georgia, the center said in a statement.
She was described by President Carter as “an extension of myself.”
The Carter Center announced earlier on Friday that the former first lady had entered hospice care.
In May 2023, she was diagonosed with dementia.
Former President Jimmy Carter, aged 99, commenced home hospice care in February after a series of brief hospital stays.
The Carters, the longest-married presidential couple, celebrated their 77th wedding anniversary in July.
Renowned for their humanitarian efforts and mental health advocacy, Rosalynn Carter co-founded the Carter Center with her husband during his post-presidency, aiming to promote global peace and health.
They jointly undertook international travels to various hotspots, such as Cuba, Sudan, and North Korea, where they monitored elections and worked towards eliminating diseases like Guinea worm disease and other neglected tropical diseases.
Jimmy Carter was awarded the Nobel Peace Prize in 2002 for his contributions to peace.
The former first lady, Rosalynn Carter, played a significant and influential role in the White House during her husband’s presidency from 1977 to 1981.
Together with President Jimmy Carter, she worked to rebuild the nation’s trust in the presidency, especially as the country was still recovering from the aftermath of the Watergate scandal, according to CNN.
Jill Stuckey, a longtime friend of the Carters, said that the former president trusted his wife “above and beyond everybody else.”
“Rosalynn has always been that trusted adviser that is selfless. He knows for sure that she is looking out for others. And I don’t know if President Carter would have been president without Rosalynn,” Stuckey said.
Recently, the couple made a surprise visit to the Plains Peanut Festival in Plains, Georgia, in anticipation of the former president’s 99th birthday.
In his 2015 memoir “A Full Life: Reflections at 90,” Jimmy Carter celebrated the couple’s “good health” and shared that they “look to the future with eagerness and confidence.” But, he said, they were also “prepared for inevitable adversity when it comes.”