Cricket Australia said the 44-year-old would support head coach Darren Lehmann as a consultant, providing specialist training for the squad's spinners.
The Australia T20 squad begins a three-match series against South Africa on March 9, before heading to compete in Bangladesh.
"We believe our national teams can really benefit from more specific skill-based coaching as and when it is needed," Lehmann said.
"This will mean that from time to time we will enlist the support of experts in their craft to work with our players and share their experiences."
Lehmann said spin bowling would be crucial to eighth-ranked Australia's chances in Dhaka.
"There's no better person than Shane to help guide the spinners we select in that squad.
"He was a gifted cricketer and remains passionate about spin bowling and seeing our players be the best that they can be. We're thrilled to have him on board," said Lehmann.
Added Warne, who retired in 2007 with a then world-record 708 Test wickets: "I'm excited to be working with Australia's spinners in South Africa," he said.
"I'm looking forward to helping them with some intense bowling preparation ahead of the World Twenty20, where we'll specifically work on tactics and mindset," he added.
