The interior fit out (see photo gallery right) consists of a series of themed areas, including the great barrier reef, the beach-themed café Esky and an IT support area where those with laptop-related tech issues can "Wii while they wait" for them to be resolved.
Google's general manager for Australia and New Zealand, Karim Temsamani, welcomed the Governor-General, Ms Quentin Bryce, and Google's 350-odd employees to the new space, which was still being readied over the weekend.
"Moving into our headquarters in Pyrmont is really the next stage of Google's investment in Australia," Temsamani said.
"The internet makes a substantial contribution to Australians of all ages. We're committed to continuing to invest here in Australia and in [this country's] vibrant digital economy."
Google also announced that public transit information for Sydney's light rail and monorail network and Canberra's bus network would be added to Google Maps later this month.
The company's head of engineering, Alan Noble, also said the new Australian headquarters would host a developer day on June 19 to help local developers "build out the wave platform" unveiled in San Francisco last week.