Ian Elkins responded after animal welfare officials warned the life of the merino sheep could be in danger because it was so woolly.
Sheep can develop serious health issues if they are not regularly shorn.
The animal - believed to be male - was "four-to-five times its normal size," welfare official Tammy Ven Dange said.
"It's definitely one of the biggest sheep we've ever seen," Ms Ven Dange, head of the RSPCA in the Australian Capital Territory, was quoted as saying by the AFP news agency.
She added that the animal was "pretty stressed out" around human beings after what was probably years of solitude.
RSPCA officials had initially wanted to shear the animal themselves, but later decided to wait for an expert.
Mr Elkins, a four-time Australian Shearing Championship winner, said removing the fleece "could be one of my biggest challenges yet".
In 2004, Shrek the New Zealand sheep was found after six years on the loose.
The animal - also a merino - later lost his giant 27kg (60lb) fleece in a televised shearing broadcast live around the world.
The country's most famous sheep died in June 2011.
Australia's national shearing champion has been urgently called in to help after a heavily overgrown sheep was found near the capital Canberra.