"Nathan is tough and uncompromising and has the respect and loyalty of all his team-mates," Mitchell said.
"He's a decision-maker both on and off the field, but is humble and ready to listen."
Sharpe claimed his second Rugby Medal for Excellence on Friday, a measure of his respect among his peers.
He has been the shining light in a poor 2005 for the Wallabies, playing all 13 Tests, mainly as vice-captain.
"This is a great moment for me. I will do everything in my power to honour the position," Sharpe said.
Another Wallaby, number eight Scott Fava, was named vice-captain. Fava made his debut for the Wallabies in last month's Test against England. Ã0Â
The decision comes after the Force undertook a three-day training camp on Rottnest Island off the coast of Western Australia.