Khalid Yasin, an American living in England, and Muhammad Raza from Pakistan will not be allowed to come to Denmark before 15 June 2019 at the earliest.
Their names have been added to the list of those considered extremist preachers that was started on 2 May 2017.
With their addition, the list now comprises eight people.
The immigration and integration minister, Inger Støjberg, said: "I'm very pleased that two new extremist preachers have been added to the list. It shows me that the immigration service is doing its job and is keeping abreast of checking who fulfils the criteria to be put on the list."