Campese will arrive in Durban next month to do specialist work with the backline and the Sharks academy.
The former Wallaby has tried to get involved in the Australia set-up in the past but claims his own ideas did not correspond with those of the ARU.
He told the Australian newspaper: "In Australia it seems you've got to be in that little inner circle to get a coaching job.
"Maybe it helps if you want to be a yes man. Perhaps that improves your chances of getting selected. I don't know.
"But I remember going for the Australian sevens coaching job a few years ago and the first question I was asked was how I got on with the Wallaby coach of the time, Rod Macqueen.
"I knew then I was never going to get the job. It seemed my chances of coaching here were pretty slim because my idea of playing rugby is not the same as other people like, say, Eddie Jones.
"This opportunity in South Africa is new for me. Rugby is an international game and you only have to look at cricket and how former players from Australia have headed elsewhere because other countries wanted to tap into their knowledge."
Sharks coach Dick Muir is delighted with his coaching coup.
"It (his signing) is a loss for his own country but we welcome him with open arms," Muir said.