Folau had all but inked the new contract as early as October last year, telling media of his decision to commit for the long-term ahead of the third Bledisloe Cup match in Tokyo.
This new agreement, though, was not officially confirmed until Saturday morning.
In a statement, Folau expressed his gratitude to Australian rugby for giving him an opportunity back in 2013, when he joined the Waratahs from AFL team the GWS Giants.
“I’m really grateful to Rugby Australia and the Waratahs for all they have done for me," he said.
