The event hosted by Attorney General George Brandis is a high priority for the Australian Government, and will be opened by Prime Minister Tony Abbott.
Malaysia, New Zealand, Singapore, Japan, Laos and Vietnam are all sending ministerial representatives to the summit, to be held on Thursday and Friday.
Indonesia has declined sending a ministerial representative, but will be represented by its Ambassador and officials. Other countries sending officials include Thailand, India and China.
In a statement outlining the objectives of the Summit, Mr Brandis said the focus is to identify and develop practical resources and strategies to address the shared threat post by terrorist propaganda and exploitation of the internet.
“Government, civil society and industry participants from over 30 nations around the region will discuss ways to improve regional coordination and increase capacity to challenge terrorist propaganda and recruitment," he said.
"The Summit provides an important platform for participants to collaborate to highlight the lies of extremist groups, develop counter narratives and turn vulnerable individuals away.”
Organisers have not provided any information about why Indonesia is not sending a ministerial representative.
Bilateral ties between Australia and Indonesia has been strained since the execution of Bali nine ringleaders Myuran Sukumaran and Andrew Chan.
Australia recalled its Ambassador to Jakarta over the incident.