Ron Godwin, the university's executive vice president, said Falwell, 73, was found unresponsive around 10:45 a.m. and taken to Lynchburg General Hospital. "CPR efforts were unsuccessful," he said.
Godwin said he was not sure what caused the collapse, but he said Falwell "has a history of heart challenges."
"I had breakfast with him, and he was fine at breakfast," Godwin said. "He went to his office, I went to mine, and they found him unresponsive."
Falwell had survived two serious health scares in early 2005. He was hospitalized for two weeks with what was described as a viral infection, then was hospitalized again a few weeks later after going into respiratory arrest. Later that year, doctors found a 70 percent blockage in an artery, which they opened with stents.
Falwell credited his Moral Majority with getting millions of conservative voters registered, electing Ronald Reagan and giving Republicans Senate control in 1980.
"I shudder to think where the country would be right now if the religious right had not evolved," Falwell said when he stepped down as Moral Majority president in 1987.
The fundamentalist church that Falwell started in an abandoned bottling plant in 1956 grew into a religious empire that includes the 22,000-member Thomas Road Baptist Church, the "Old Time Gospel Hour" carried on television stations around the country and 7,700-student Liberty University. He built Christian elementary schools, homes for unwed mothers and a home for alcoholics.
He also founded Liberty University in Lynchburg, which began as Lynchburg Baptist College in 1971.
Liberty University's commencement is scheduled for Saturday, with former U.S. House Speaker Newt Gingrich as the featured speaker.
In 2006, Falwell marked the 50th anniversary of his church and spoke out on stem cell research, saying he sympathized with people with medical problems, but that any medical research must pass a three-part test: "Is it ethically correct? Is it biblically correct? Is it morally correct?"
Falwell had once opposed mixing preaching with politics, but he changed his view and in 1979, founded the Moral Majority. The political lobbying organization grew to 6.5 million members and raised $69 million as it supported conservative politicians and campaigned against abortion, homosexuality, pornography and bans on school prayer.
Falwell became the face of the religious right, appearing on national magazine covers and on television talk shows. In 1983, U.S. News & World Report named him one of 25 most influential people in America.
In 1984, he sued Hustler magazine for $45 million, charging that he was libeled by an ad parody depicting him as an incestuous drunkard. A federal jury found the fake ad did not libel him, but awarded him $200,000 for emotional distress. That verdict was overturned, however, in a landmark 1988 U.S. Supreme Court decision that held that even pornographic spoofs about a public figure enjoy First Amendment protection.
The case was depicted in the 1996 movie "The People v. Larry Flynt."
With Falwell's high profile came frequent criticism, even from fellow ministers. The Rev. Billy Graham once rebuked him for political sermonizing on "non-moral issues."
Falwell quit the Moral Majority in 1987, saying he was tired of being "a lightning rod" and wanted to devote his time to his ministry and Liberty University. But he remained outspoken and continued to draw criticism for his remarks.
Falwell was re-energized after moral values issues proved important in the 2004 presidential election. He formed the Faith and Values Coalition as the "21st Century resurrection of the Moral Majority," to seek anti-abortion judges, a constitutional amendment banning same-sex marriage and more conservative elected officials.
The big, blue-eyed preacher with a booming voice started his independent Baptist church with 35 members. From his living room, he began broadcasting his message of salvation and raising the donations that helped his ministry grow.
"He was one of the first to come up with ways to use television to expand his ministry," said Robert Alley, a retired University of Richmond religion professor who studied and criticized Falwell's career.