Home Secretary Charles Clarke scrapped the exclusion order imposed by predecessor Michael Howard in 1995.
The Daily Telegraph said Mr Moon would arrive soon to attend a conference.
Home Secretary Charles Clarke was quoted in the Telegraph saying he had considered excluding Mr Moon, but had not had sufficient reason.
Mr Howard said a visit by him could threaten public order.
The 86-year-old Korean is perhaps best-known for his church's mass weddings, involving tens of thousands of couples.
He has always strenuously denied allegations the church uses inappropriate methods to recruit new members.
The Daily Mail was locked in a lengthy libel battle in the 1980s over its allegations of brainwashing.
A Home Office spokesman said: "We can confirm that the exclusion order against him has been lifted.
"We keep exclusions under review. The Unification Church in the United Kingdom is extremely small and any visit by its founder is considered unlikely to pose any threat to the public order of this country."
The conference would see a 1,000-strong audience, including theologians and academics, listen to a lecture by Mr Moon on world peace, the Telegraph said.
The Unification Church was at one point said to have as many as 500,000 followers although that number is believed to have dropped.