The Lindt Cafe in Sydney's Martin Place will reopen this Friday, three months after the siege that claim

Gunman Man Haron Monis took 17 people hostage in the cafe in Sydney's CBD on December 15, leading to the deaths of cafe manager Tori Johnson, 34, and barrister Katrina Dawson, 38, along with Monis.

The cafe's doors will officially open at 10:00am (AEDT) on Friday and standard trading hours will resume on Saturday.

In a statement released on Facebook, Lindt Australia chief executive Steve Loane said the company discussed with the cafe's staff whether to reopen.

"Overwhelmingly, the feeling was that reopening and moving forward is the best thing to do for everyone affected," he said.

A plaque dedicated to Mr Johnson and Ms Dawson has been installed inside the cafe, he said.

"Again, it was felt this was the right thing to do, to remember Tori and Katrina and their spirit," Mr Loane said.

Mr Loane thanked the public for their support in the wake of the siege.

"On behalf of our staff and those affected, we wish to express again our deepest gratitude for the support we have received from the broader public," he said.

"It has truly been a source of strength for everyone and has helped us in our decision to reopen the cafe and move forward."

He asked that the public respect the cafe staff's privacy as they resumed their working lives.

"To this end, we would ask that our staff's personal privacy is respected as they go back to work and the job they enjoy so much," he said.