American Christian radio host Harold Camping stated that the rapture and Judgment Day would take place on May 21, 2011, and that the end of the world would take place five months later on October 21, 2011.

Camping, who was then president of the Family Radio Christian network, claimed the Bible as his source and said May 21 would be the date of the rapture and the day of judgment "beyond the shadow of a doubt". Camping suggested that it would occur at 6 p.m. local time, with the rapture sweeping the globe time zone by time zone, while some of his supporters claimed that around 200 million people (approximately 3% of the world's population) would be 'raptured'. Camping had previously claimed that the rapture would occur in September 1994.

The vast majority of Christian groups, including most Protestant and Catholic believers, did not accept Camping's predictions; some explicitly rejected them, citing Bible passages including the words of Jesus stating "about that day or hour no one knows" (Matthew 24:36). An interview with a group of church leaders noted that all of them had scheduled church services as usual for Sunday, May 22.Following the failure of the prediction, media attention shifted to the response from Camping and his followers. On May 23, Camping stated that May 21 had been a "spiritual" day of judgment, and that the physical rapture would occur on October 21, 2011, simultaneously with the destruction of the universe by God. However, on October 16, Camping admitted to an interviewer that he did not know when the end would come, and made no public comment after October 21 passed without his predicted apocalypse.In March 2012, Camping "humbly acknowledged" in a letter to Family Radio listeners that he had been mistaken, that the attempt to predict a date was "sinful", and that critics had been right in pointing to the scriptural text "of that day and hour knoweth no man". He added that he was searching the Bible "even more fervently [...] not to find dates, but to be more faithful in our understanding."

Harold Egbert Camping (July 19, 1921 – December 15, 2013) was an American Christian radio broadcaster and evangelist. Beginning in 1958, he served as president of Family Radio, a California-based radio station group that, at its peak, broadcast to more than 150 markets in the United States. In October 2011, he retired from active broadcasting following a stroke, but still maintained a role at Family Radio until his death. Camping is notorious for issuing a succession of failed predictions of dates for the End Times, which temporarily gained him a global following and millions of dollars of donations.Camping first predicted that the Judgment Day would occur on or about September 6, 1994. When it failed to occur, he revised the date to September 29 and then to October 2. In 2005, Camping predicted the Second Coming of Christ to May 21, 2011, whereupon the saved would be taken up to heaven in the rapture, and that "there would follow five months of fire, brimstone and plagues on Earth, with millions of people dying each day, culminating on October 21, 2011, with the final destruction of the world."His prediction for May 21, 2011 was widely reported, in part because of a large-scale publicity campaign by Family Radio, and it prompted ridicule from atheist organizations and rebuttals from Christian organizations. After May 21 passed without the predicted events, Camping said he believed that a "spiritual" judgment had occurred on that date, and that the physical Rapture would occur on October 21, 2011, simultaneously with the final destruction of the universe by God. Except for one press appearance on May 23, 2011, Camping largely avoided press interviews after May 21, particularly after he suffered a stroke in June 2011. After October 21, 2011, passed without the predicted apocalypse, the mainstream media labeled Camping a false prophet and commented that his ministry would collapse after the "failed 'Doomsday' prediction".Camping was reported to have retired from his position at Family Radio on October 16, 2011, only days before his final prediction for the end of the world. However, his daughter later clarified that he had not retired outright, but was maintaining a role at Family Radio while remote working. Camping admitted in a private interview that he no longer believed that anybody could know the time of the Rapture or the end of the world, in stark contrast to his previously staunch position on the subject. In March 2012, he stated that his attempt to predict a date was "sinful", and that his critics had been right in emphasizing the words of Matthew 24:36: "of that day and hour knoweth no man". He added that he was now searching the Bible "even more fervently...not to find dates, but to be more faithful in [his] understanding." After the failure of Camping's prophecies, Family Radio suffered a significant loss of assets, staff and revenue.