The 38-year-old, who won 111 caps for the Wallabies, called time on his career after a short spell with Premiership side Bristol Bears.
Smith also featured for the likes of Toulon, Lyon, Stade Francais and Wasps after beginning his career with Super Rugby club the Brumbies.
The flanker, fifth on the list of Australia's most-capped players, stressed he will end his playing days with no regrets.
"Finally the day has come where I officially announce my retirement from professional rugby," Smith said.
