He has been appointed head coach of Romanian side Timisoara Saracens who played Edinburgh in the European Rugby Challenge Cup last season.
The Australian was Scotland’s first-ever overseas head coach from December 2003 to April 2005, but the team won just three matches from 17 while he was in charge.
On his new position he said: “I am delighted to begin working with Timisoara Saracens. I have been very impressed with the club’s highly ambitious plans to succeed.”
One of his first signings for the club is Will Helu.
The 31-year-old Tongan internationalist spent the last two seasons at Edinburgh, but due to injury failed to make an impact.
Williams said of Helu: “He is an experienced players with an impressive CV. He has shown up well in training.”