At 10 a.m., a non-religious service will be held for Doré's family, invited friends and dignitaries.
Citizens can watch the service on a giant screen that will be set up in Place Vaquelin, the public square just adjacent to City Hall in Old Montreal.
Doré will lie in state in the Hall of Honour at City Hall this weekend.
The former mayor's family will receive only friends and dignitaries on Saturday.
Members of the public who wish to pay their final respects can do so on Sunday. The doors to Montreal City Hall will be open to all from 10 a.m. to 5 p.m.
Doré, who served as Montreal's 39th mayor from 1986 to 1994, died on June 15, 2015 of pancreatic cancer.
"After more than 20 years since he was mayor, Montrealers still recognize at what point the legacy of Jean Doré is important and deserves to be saluted," said Montreal Mayor Denis Coderre.
People who wish to make a contribution in honour of Doré can make a donation to the Jean Doré Fund, which raises money for pancreatic cancer research.