Sainz was forced out of the Italian team by Lewis Hamilton, with Williams subsequently securing his signature as a result and a major coup ahead of the new campaign
Williams also has some exciting young stars within their junior driver program, including Zak O'Sullivan and Luke Browning, with the future looking bright for the Grove outfit.
Now, Williams have announced a key off-track signing, with former world champion Jacques Villeneuve joining in an ambassadorial role.
Villeneuve drove with Williams between 1996-1998, winning the 1997 world championship title after a fierce battle with Michael Schumacher.
Following his departure from the sport back in 2006, Villeneuve has become a pundit, regularly appearing on Sky Sports F1's coverage at race weekends.
Jacques Villeneuve won the 1997 world championship
Williams announced in an official statement that Villeneuve will be taking up an ambassador role, alongside current ambassadors Jenson Button and Jamie Chadwick.
In an official press release, Villeneuve spoke of his excitement at rejoining the Williams team: "Williams has been a crucial part of my life, filled with fond memories," he said.
"I am ecstatic to be part of the family again, and to help celebrate the team’s heritage while supporting its future."