Scouts NSW has made the difficult decision to cancel the 2020 Cuboree, in consultation with the Rural Fire Service.
Cubs from Taree, Wingham and Forster were to attend.
"We are incredibly grateful to the support and advice we've been given by the RFS, and we acknowledge the pressure their teams are facing during these unprecedented bushfires across NSW," Scouts NSW chief commissioner, Neville Tomkins OAM JP said.
"While we are disappointed for the hundreds of young people who were planning to attend, our thoughts are with those members of our community who have lost loved ones, animals and homes as a result of the fires.
"We're proud that many of our local Scout Groups are doing everything they can to help those who've been affected. Scouts NSW is part of the local community, and we're always willing to give a helping hand."
The Cuboree was to be held at Cataract Scout Park south of Sydney.