Controversial US pastor Terry Jones has been excluded from the UK for the public good, the Home Office has said.
The pastor had been invited to the UK to give an address to the right-wing group England Is Ours in Milton Keynes.
Mr Jones gained international attention for threatening to burn a copy of the Koran outside his church in the US on the anniversary of the 9/11 attacks.
A Home Office spokesperson said the government "opposes extremism in all its forms".
He said: "Numerous comments made by Pastor Jones are evidence of his unacceptable behaviour.
"Coming to the UK is a privilege not a right and we are not willing to allow entry to those whose presence is not conducive to the public good.
"The use of exclusion powers is very serious and no decision is taken lightly or as a method of stopping open debate."
Mr Jones - who is pastor of the Dove World Outreach Center in Gainesville, Florida, which has fewer than 50 members - came to prominence in September after he announced plans for his "International Burn a Koran Day".
His plan was internationally condemned and sparked many demonstrations around the world. He eventually called off his protest.