More than 100 of the victims had ties to Canada, and at least 55 were Canadian citizens.
The Association of Families of Flight PS752 Victims group organized the service.
Voices of loved ones — some wishing to talk to those who died, others wanting to know their last thoughts — played over videos and photos of faces young and old.
Biographies of the victims were to be read throughout the night and outdoor rallies were to take place later in various cities, including Toronto, Montreal and Edmonton.
The plane was bound for Kyiv on Jan. 8, 2020, when it was shot out of the sky shortly after takeoff from Tehran’s Imam Khomeini International Airport.