Communications Minister Malcolm Turnbull and Minister for Human Services Marise Payne said the data centre, in Canberra's Fyshwick district, will be shared by agencies to streamline government spending.
"The security and reliability offered by this new facility means the government is in a strong position to expand the services offered through its various digital channels and provide services to various Commonwealth agencies.
Turnbull said the data centre had been designed to ensure an energy-conscious and cost-effective use of resources.
"The building is nearly entirely self-sufficient with its water requirements thanks to a clever water retention system, and an LED lighting system ensures power isn't used unnecessarily," he said.
The opening of the new site marks the "near completion" of the Department of Human Services' data centre consolidation project, which will save taxpayers an estimated $24.5 million in leasing costs over the next decade.