Bishop Milutin Knezevic, 71, and two other priests from the Valjevo diocese tested positive for coronavirus last week. He died overnight in a Belgrade hospital, his diocese said in a statement without elaborating.
The Serbian Orthodox Church wields considerable influence in some former republics of old Yugoslavia with around 12 million members mainly in Serbia, Montenegro and Bosnia.
After Serbia earlier this month declared state of emergency and suspended public gatherings to curb the spread of the coronavirus, Orthodox Patriarch Irinej banned all services and asked faithful to watch them on TV.
But the church for days continued with its practice of delivering communion using a single spoon dipped in wine for the faithful gathered outside churches, before last week limiting communion to individuals in their homes.
The church has also recommended funerals with few people and rescheduled baptisms until after the pandemic subsides.
To curb transmission of the virus, Serbian authorities have shut down all restaurants and cafes, imposed a curfew from 5 p.m. to 5 a.m. and closed the country's borders.
President Aleksandar Vucic said on Sunday evening the state could consider a two-week, 24-hour lockdown in the coming days.So far, 13 people in Serbia, out of a population of 7 million, have died from the coronavirus and 741 have been diagnosed with the infection.