He died at his home in Montreat, North Carolina, a spokesman for the Billy Graham Evangelistic Association said.
In a 60-year career, he is estimated to have preached to hundreds of millions of people around the world.
Former presidents are among the many who have been paying tribute. President Trump called him "great" and a "very special man".
After becoming one of the best-known promoters of Christianity in the US, Graham embarked on his global mission with an event in London in 1954.
Graham reached millions of worshippers through TV - the first to use the medium to convey the Christian message on such a scale.
Born in 1918 and raised on his family's dairy farm in Charlotte, North Carolina, Billy Graham became a committed Christian at the age of 16 after hearing a travelling evangelist.
He was ordained a minister in 1939, aged 21.
Graham's public profile was raised in the United States when he held a two-month ministry in a giant tent in Los Angeles in 1949.
His global mission took him to all corners of the world including Nigeria and communist North Korea.
An early sermon outside the US took place before 12,000 worshippers in 1954 in Harringay Arena, London.
At first ambivalent about the civil rights movement in the US, he became more sympathetic in the 1950s, preaching to racially integrated congregations.
His fiery delivery became more measured with advancing years and controversy surrounding the techniques of mass evangelism.
Graham avoided the scandals - sexual and financial - which dogged some contemporary televangelists through the decades.
A social conservative, he opposed same-sex marriage and abortion.
Graham preached his final revival meeting in New York in 2005 at the age of 86.
As the end of his life approached, he said: "I know that soon my life will be over. I thank God for it, and for all He has given me in this life. But I look forward to Heaven."
'Plus side of history' - tributes
In a tweet, President Donald Trump called him a special man.
He wrote: "The GREAT Billy Graham is dead. There was nobody like him! He will be missed by Christians and all religions. A very special man."
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