Radio broadcaster Harold Camping predicted that the world would end on this date.

Harold Egbert Camping 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.

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.