The reopening ceremony saw the installation of permanent commemorative plaques for 34-year-old cafe manager Tori Johnson and 38-year-old barrister Katrina Dawson; they were both killed after being held captive with 16 others for 16 hours in the final minutes of the December 15-16 standoff.
Earlier on Friday, New South Wales Premier Mike Baird entered the cafe to talk to the staff, including Joel Herat, who was one of several staff members to survive the siege and who returned to work on Friday.
For his part, Steve Loane, chief executive of Lindt Australia, touted the decision to reopen the cafe.
"After the tragic events that happened in December we discussed this reopening with our staff and gave a lot of thought to next steps.Overwhelmingly, the feeling was that reopening and moving forward is the best thing to do for everyone affected", Loane said.
Ahead of the reopening, dozens of Sydney residents gathered in front of the cafe, with many clutching flowers in memory of the victims.