The opening is seen as a way to show support for Greenland and Denmark - and to counter US President Donald Trump's aggressive rhetoric about the island.
"In a way, it is a victory for Greenlanders to see two allies open diplomatic representations in Nuuk," Jeppe Strandsbjerg, a political scientist at the University of Greenland, told AFP.
Attending Friday's ceremonies will be Canada's Foreign Minister Anita Anand and Denmark's Lars Løkke Rasmussen, among others.
On Thursday, a plane carrying Canadian Inuit also landed.
"It feels really important to support our Inuit compatriots, especially regarding sovereignty," Minnie Annahatak, from Nord-du-Québec, told The Canadian Press.
