"There are some outstanding young men coming through the schools system. I want to create a strong connection with the Super Rugby and national age grade Coaches and help them achieve their goals, which will benefit the Wallabies in time.
"When I met Raelene Castle, I was really impressed with her plans for the future of Australian Rugby and I'm keen to be part of that.
"We've loved our time here in Glasgow. The Coaching group and management are absolutely world class. The work ethic and passion of the players has been incredible, and we will miss them."
Rugby Australia Chief Executive, Raelene Castle said: "This is a massive coup for Australian Rugby, Dave Rennie was the clear standout candidate for the job, and we're thrilled to have secured his services."
Rennie has been linked with the Australian job ever since Michael Cheika stepped down after the Wallabies' disappointing World Cup campaign.
The deal will keep Rennie in charge of the Wallabies until the 2023 World Cup in France.
Earlier this month, Rennie revealed that he was being considered by New Zealand Rugby to become the next All Blacks coach.
"Obviously it's flattering, it's humbling. They've [New Zealand] always been such a great side," he told STV news in Scotland.
"I guess I haven't had a lot of time to dwell on that because I'm totally focused on what I'm doing here.
"They've probably made contact with a number of Kiwis who are coaching over this way about interest for the role.
"They will have a process where they interview then make an appointment in the new year."
However, many reports claimed that Rennie was already close to signing with the Wallabies, leaving the All Blacks job likely to be between Ian Foster and Scott Robertson.
Last month reports claimed Rugby Australia had informed its staff that Rennie would take the job.
Rennie has never coached at an international level, but led the Chiefs to two Super Rugby titles in 2012 and 2013, and has been coaching in Scotland since 2017.
