"Ensuring it can recover quickly will stimulate economic activity and restore jobs at home and abroad."
The purchases will be made from a range of manufacturers via the global COVAX Facility plan, which aims to ensure virus vaccines are shared with all nations.
Australia will provide a range of support with the vaccine doses, including vaccine safety and effectiveness assessments, advice to each nation's regulatory authorities, technical support as well as passing along vital World Health Organisation information.
The plan will be rolled out over three years to help countries, such as Timor-Leste to Australia's north, achieve full virus immunisation coverage.
"A fast, safe vaccine rollout in the Pacific and Southeast Asia will mean we are able to return to more normal travel, tourism and trade with our key partners in the region," Ms Payne said.
Humanitarian agency United Nations Children's Fund welcomed the news.
"Until the pandemic is over for everyone, it's not for anyone and this support for South East Asia and the Pacific to introduce a successful vaccine is a strong contribution towards ensuring the health of all Australians and our neighbours," UNICEF Australia researcher Alice Hall said.
Save the Children Fund said the pledge is a good start but more will need to be done.
"A vaccine is still a long way off and the pandemic is expected to push a further half a million people in the Pacific into poverty," deputy chief executive Mat Tinkler said.
"Pacific economies - many heavily reliant on tourism - have been decimated."
Mr Tinkler called on the federal government to also increase support for impoverished people in the Pacific.
"We are urging Australia to work with the Pacific to create a social protection system that reaches the poorest children and families," he said.
"Strong social intervention would save lives now and is in Australia's strategic interests."
The Australian government has also entered into advanced purchase agreements with Astra Zeneca-Oxford and CSL-University of Queensland for over 84 million units of vaccines.
Earlier this year, the government promised to set $80 million aside for an initiative that would help Pacific and Southeast Asian countries get cheap access to a coronavirus vaccine.