The 44-year former Hampshire skipper and world record Test wicket-taker will join up with Australia's squad in March during their tour of South Africa.
Warne will be with the side for the three Twenty20 matches, which will act as a final preparation before flying to Bangladesh for the start of the World Twenty20 on March 16.
"I'm excited to be working with Australia's spinners in South Africa," Warne said.
"I'm looking forward to helping them with some intense bowling preparation ahead of the World Twenty 20, where we'll specifically work on tactics and mindset."
Coach Darren Lehmann has regularly sought former Australia players out to work with his squad since taking over in June.
Warne, who captained Hampshire between 2004-2007 inclusive, spoke with Australia's spinners during the summer's Ashes series in Manchester, while former right-armer Graham McKenzie helped lead a training session at the WACA Ground on Thursday ahead of the fourth one-day international against England.
"We believe our national teams can really benefit from more specific skill-based coaching as and when it is needed," he 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.
"In the case of the ICC World Twenty 20, we believe spin bowling will be critical to success. 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."
Australia Twenty20 captain George Bailey welcomed Warne's appointment.
"I'm thrilled to have him on board as a spin coach, but I think he brings so much more to the table," said the man who appeared for Hampshire last summer.
"He'd be one of the leading thinkers on T20 in the world, tactically.
"He's highly respected by the group. I think it's a great appointment.
"Boof's (Lehmann) been really keen to get past greats and past players around the group.
"Garth McKenzie at training today was a real thrill for the boys. You can't get enough of it I don't think."
Bailey will captain a weakened Australia team in tomorrow's fourth one-day international against England in Perth after the starting XI was named a day early.
Michael Clarke, David Warner and Brad Haddin have been rested from the team that clinched the five-match series in Sydney on Sunday, while spinner Xavier Doherty has been left out.
Replacing them are Bailey, who has overcome a hip problem, Steve Smith, Matthew Wade and Mitchell Johnson.