Williams have announced that Mike Coughlan has stepped down and will be replaced by Pat Symonds.
A statement from the Grove squad on Tuesday confirmed that Coughlan, who has been with Williams since 2011, stepped down as technical director and will leave the team with immediate effect.
In a separate announcement, Williams also revealed that Symonds will join from Marussia and will take up the role of chief technical officer on August 19.
Symonds has been part of the Marussia set-up since February 2011, acting as a consultant.
"I have thoroughly enjoyed my time with the Marussia F1 Team over the course of the past two-and-a-half seasons," Symonds said.
"The team has developed immeasurably during that time and it now has all the right people and resources in place to achieve great things in the future. I wish the team the success it so richly deserves."
Symonds was part of the Benetton and Renault set-ups that oversaw Michael Schumacher and Fernando Alonso's successes, winning four Drivers' Championships and three Constructors' titles.
"I'm delighted that Pat is joining the team," Sir Frank Williams said. "His technical capabilities and sporting successes speak for themselves and I'm sure that his knowledge and leadership will contribute considerably to the success that all of us at Williams are working hard to achieve."
Symonds said: "Williams is a team steeped in success and engineering excellence and I'm honoured to be asked to play a role in returning the team to its rightful place at the pinnacle of Formula One. Sir Frank, Mike and Claire have put in place the foundations for success and I'm immensely excited to begin this new challenge."