Williams have been bought by United States investment firm Dorilton Capital.
The takeover of the Formula One team, which was put up for sale in May, was announced on Friday.
The team will continue to race under the Williams name and do not plan to relocate from their base in Grove.
The purchase has been concluded in the week that all 10 F1 teams signed up to the Concorde Agreement, aimed at creating a more level playing field from 2021.
According to a statement, Frank Williams, the founder of the team, said the takeover "delivers the best outcome for the company's shareholders and secures the long-term success of the Williams Formula One team".
Deputy team principal Claire Williams said: "When we started this process, we wanted to find a partner who shared the same passion and values, who recognised the team's potential and who could unlock its power.
"In Dorilton we know we have found exactly that. People who understand the sport and what it takes to be successful. People who respect the team's legacy and will do everything to ensure it succeeds in the future.
"As a family we have always put our team first. Making the team successful again and protecting our people has been at the heart of this process from start. This may be the end of an era for Williams as a family owned team, but we know it is in good hands.
"The sale ensures the team's survival but most importantly will provide a path to success. We are enormously grateful to Dorilton for the faith they have shown in our team and we look forward to working with them now. I would also like to thank the Williams board and our advisers who have worked tirelessly over the past months to make this happen and our employees who have remained steadfastly loyal."
Williams, who entered Formula One in 1977, have won seven drivers' championships and nine constructors' championships.
However, the last of each of those came in 1997, when Jacques Villeneuve claimed his first and only title.