Sam Michael is headed to McLaren in 2012, it was announced officially on Tuesday.
Earlier, the rumour was doing the rounds on the microblogging website Twitter.
Amid Williams' struggle for performance in recent years, Australian Michael resigned his post as technical director in May. The Oxfordshire based team said on Tuesday his last race will be Singapore next weekend.
In 2012, the 40-year-old will then return to the paddock as McLaren's new sporting director.
He will have "responsibility for the development and management of the team's trackside operations", a McLaren statement said.
"I am delighted that Sam has found a new role that will enable him to continue to apply his energy, passion and experience to formula one," commented Sir Frank Williams in a separate statement.
Williams has already replaced Michael with Mike Coughlan as well as Mark Gillan, who will start work next week.