Roberts, founder of the university in Tulsa, Okla., that is named after him, died from complications of pneumonia at a Newport Beach hospital, family spokeswoman Melany Ethridge said. He had suffered a fall over the weekend.
Roberts pioneered the use of television and computerized databases to spread the Gospel and raise hundreds of millions of dollars -- a formula followed today by numerous other ministries.
Using sophisticated and relentless direct-mail campaigns, Roberts asserted that God generously rewarded financial acts of faith performed in God's name. This credo became known as the "prosperity gospel."
"It gives people hope and expectation that seeds sown to God will be multiplied back in every area of life," Roberts wrote in his 1995 autobiography, "Expect a Miracle: My Life and Ministry."
Roberts brought Pentecostalism -- which promotes charismatic worship including faith healings and talking in tongues -- to the American mainstream, giving it a newfound sense of legitimacy among the middle class and within other denominations.
"More than any other person, he should be credited with starting the charismatic movement in mainline religion," said Vinson Synan, dean of the divinity school at Regent University in Virginia and a historian of the Pentecostal movement. "He brought [divine] healing into the American consciousness."
Worldwide, the charismatic branch of Christianity -- now found in mainstream denominations as well as Pentecostalism -- grew from an estimated 20 million to 600 million during Roberts' seven decades of ministry. His international broadcasts and crusades deserve a large part of the credit for the increase, Christian scholars said.
"With the passing of Oral Roberts the world has lost one of the most inspiring voices for Christ of this century," Robert H. Schuller, founding pastor of the Crystal Cathedral in Garden Grove, said in a statement. "Twentieth century history of Christianity will name Oral Roberts as the voice that brought the Pentecostal movement to be taken seriously by mainline Christianity."
In the 1970s, Roberts' prime-time TV specials drew 40 million viewers, and he appeared frequently on talk shows hosted by Johnny Carson, Dinah Shore and Merv Griffin. The preacher also had a half-hour program -- "Something Good Is Going to Happen to You" -- that aired Sundays.
By 1980, Roberts was recognized by 84% of Americans, close behind the sitting U.S. president and fellow evangelist Billy Graham and 40 points ahead of the next religious figure.
"Not bad," he once said, "for a poor boy with a speech impediment who was supposed to die of tuberculosis before he was 20."
At the time of his death, however, Roberts' ministry and celebrity had been in decline for years, a drop-off accelerated by a prophecy the preacher made 22 years ago that "God will call me home" unless $8 million was raised for scholarships to Oral Roberts University by March 31, 1987.
The money was raised, but by then Roberts had become a figure of ridicule to many inside and outside the Christian world.
With dwindling revenues -- they once stood at more than $100 million a year -- the televangelist was forced in 1989 to downsize his ministry, laying off 250 employees, closing Tulsa's City of Faith medical center and an adjoining medical school, and selling vacation homes and luxury cars to raise money.
A heart attack in 1992 forced him into semi-retirement, though he remained the chancellor of the university. He spent most of his final years in a Newport Beach condominium with his wife, Evelyn, who died in April 2005. They had been married 66 years.
Granville Oral Roberts, the youngest of five children, was born in a log cabin near Ada, Okla., on Jan. 24, 1918, the son of a part-time preacher and farmer. His mother was part Cherokee.
Roberts was raised in a Pentecostal-flavored Methodist church, and the family later joined the Pentecostal Holiness Church.