Williams will retain the services of drivers Felipe Massa and Valtteri Bottas for next season.
The Grove-based squad enjoying a breakthrough season this year confirmed the line up ahead of the Italian Grand Prix as a result of successful talks with its drivers.
Massa, who joined the squad this year after eight years at Ferrari, was already under contract for next year but his team-mate Bottas did have an option to leave the team at the end of the season.
After recording four podiums in the last five races, the team has moved swiftly to retain Bottas, who has emerged as one of the brightest young drivers on the grid.
The Finn is highly regarded by team boss Frank Williams having joined the team as a test driver in 2010.
“Felipe is a pleasure to work with and combines raw pace with a wealth of experience,” said Sir Frank Williams.
“We have known for many years that Valtteri is a very special talent and in the FW36 we have given him a car that is allowing him to demonstrate his skills.
“The team is having a much improved 2014 season and the skill of our drivers and their feedback to our engineers has proved crucial in this.
“This announcement gives us excellent stability for 2015, but of course we are very much focusing our attention on maximising the full potential of the FW36 in the remaining seven races of this season.”