The list includes two Saudis, a Canadian, a Syrian, and two Americans, including pastor Terry Jones who burned copies of the Quran in 2011.
The blacklist "sends a clear signal that travelling fanatical religious preachers who try to undermine our democracy and fundamental values of freedom and human rights are not welcome in Denmark," the immigration and integration ministry said in a statement.
The centre-right government has undertaken a systematic hunt for religious fanatics, announcing plans in May 2016 to establish a blacklist after a hidden-camera documentary exposed radical preachers in Danish mosques.
”There's a matter of principle in saying that there are people we don't want on Danish soil, coming here and preaching hate. We do not want people here if they are coming to incite terror or to incite assault or violence against Jews and homosexuals,” immigration minister Inger Støjberg told broadcaster DR.
“There are too many people listening to these imams that this is to a great degree directed at… it is a clear matter of principle that says that it is these kind of people we don't want within our borders,” she said.
Parliament broadly approved the plan.
In 2015, a young Dane of Palestinian origin who was radicalised in prison killed two people in twin attacks in Copenhagen, first gunning down a Danish filmmaker at a debate on Islam and free speech, then killing a Jewish security guard outside a synagogue.
The same year, a Moroccan man was stripped of his Danish citizenship, acquired in 1988, for having spread books written by a cleric with close ties to Al-Qaeda.
The Scandinavian country was also the target of Muslim anger and violence worldwide after Danish daily Jyllands-Posten published cartoons of the Prophet Mohammed in 2005.
Jacob Mchangama, director of thinktank Justitia, told news agency Ritzau that he thought the ministry's list could lead to a “slippery slope”.
Pastor Terry Jones speaks to the media in Gainesville, Florida in this file photo from 2010. Photo: Scott Audette/Reuters/Scanpix
"There are six people on the list, but one of them is Terry Jones, an American pastor who burned the Quran. This shows that a person can be put on the list by doing something that would be in breach of the blasphemy paragraph if it happened in Denmark. I think that is quite far-reaching and shows that this can develop in an unpredictable manner,” he said.
The full list can of banned preachers, which can be viewed on the Danish foreign ministry website, includes the following names:
Mohamad bin Abd al Rahman bin Milhi bin Mohamad al Arefe
Terry Dale Jones
Salman Bin Fahad Alodah
Mohammad Rateb Abdalah Al-Nabulsi.