In a statement, the Serbian Orthodox Church said the Patriarch "rested with the Lord" and that the public would be informed about the details of the funeral in due course.
Church bells throughout Serbia tolled and mourners flocked to light candles as the government proclaimed three days of national mourning.
Serbian Orthodox Patriarch Irinej, who had been hospitalized with COVID-19 in a Belgrade hospital since last Wednesday, has died.
The protocol of the funeral envisages that the Serbian member of the Presidency of Bosnia-Herzegovina, Milorad Dodik, will also speak.
The large funeral was held in the Montenegrin capital, Podgorica, in violation of measures in place to stop the spread of coronavirus in the small Adriatic state.
The burial turned out to be a major coronavirus-spreading event, according to the country's health officials, with several high ranking church officials and others who were present later testing positive. They had previously downplayed the threat from the global pandemic and largely ignored bans on large gatherings and preventive measures during prayers and other church services.
Born Miroslav Gavrilovic in Vidova, a tiny village in central Serbia, Irinej served as bishop of Nis diocese before being elected 45th head of the Serbian Orthodox church following death of highly revered patriarch Pavle in 2010.
On Friday, Serbia's President Aleksandar Vucic confirmed Irinej's death, posting a photo of him on Instagram with the caption: "I was honored to know you".
Serbia, with a population of around seven million, has so far reported 110,351 COVID-19 infections, with 1,140 deaths.
Throughout his church reign, he maintained the hardline, anti-Western nationalist stance, criticizing the country's advances to the West and urging instead, closer relations with Russian Federation.
Irinej was among the rare Serbian church dignitaries who openly called for improved ties with the Roman Catholic Church.
Irinej, a fierce Serb nationalist, often criticised Western policies towards Serbia and urged close relations with Slavic ally Russian Federation.
The Serbian Orthodox Church has asked mourners to keep their distance and wear face masks in line with the anti-virus recommendations, but even priests could be seen inside the Belgrade Cathedral without masks.
Irinej adamantly opposed the independence of Kosovo, Serbia's former predominantly Albanian southern province, considered a medieval cradle of Serbian Orthodox Christianity and where some of church's most important monasteries are based.
The Orthodox Churches split from the Vatican and the Roman Catholic Church in the 11th century in an event called the Great Schism.