Patriarch Irinej, the head of the Serbian Orthodox Church, has died after contracting COVID-19, President Aleksandar Vucic says.
Church bells tolled in Belgrade and many people flocked to the capital's main St Sava cathedral to mark his death at the age of 90, a decade after becoming patriarch.
A conservative who wielded considerable political influence, Irinej was diagnosed with the coronavirus on November 4 and had been in a military hospital in Belgrade since then.
He tested positive after attending the November 1 funeral of Metropolitan Amfilohije, the Serbian Orthodox Church's senior cleric in Montenegro, who also died from COVID-19.
"I was honoured to know you. People like you never depart," President Vucic posted on Instagram.
COVID-19 has infected more than 104,000 people and killed 1110 in Serbia, a country of 7.2 million.
The Serbian Orthodox Church has about 12 million followers, mainly in Serbia, Montenegro and Bosnia, and dioceses in the United States, Australia and western Europe.
Born Miroslav Gavrilovic in a village southwest of Belgrade, Irinej opposed the independence of Kosovo, Serbia's former southern province predominantly populated by ethnic Albanians.
Serbs regard Kosovo as the cradle of Serbian Orthodox Christianity and it is home to some of the church's most important monasteries.
Irinej backed Serbia's attempts to join the European Union "if the EU respects Serbian identity, culture and religion". He opposed abortion and gay rights as a "deviation of human nature".
The election of the new Patriarch among bishops will take place in the coming months.
The head of the Orthodox Church of Greece, Archbishop Ieronymos, 82, has himself been hospitalised after being diagnosed with COVID-19.