Since 2018 the Swiss based squad has adopted the Alfa Romeo moniker, with the new deal extending that in a ‘multi-year agreement'.
In May, team boss Frederic Vasseur revealed discussions regarding the extension were ongoing, and that he was hopeful of a successful conclusion.
That has now been confirmed, with the Sauber squad to carry on under the Alfa Romeo banner.
“We are delighted to be announcing the extension of this partnership,” said Vasseur.
“Alfa Romeo have been an incredible companion over the last few years, and we are even more excited about the chapters that are yet to come.
“The new regulations are giving us the chance to make another step forward and I firmly believe we are perfectly placed to make big gains together.
“We are looking forward to our future together and to keeping moving towards the front of the grid.
“This relationship is also very important for our company as a whole, beyond the track: the work we have done in the automotive world has shown the extent of the technology and manufacturing skills of Sauber Engineering and we are confident we can continue working for Alfa Romeo on new and exciting projects that will shape the future of the car industry.”
Jean-Philippe Imparato, CEO of Alfa Romeo, added: “As an historic Italian automotive brand, Alfa Romeo was born on the racetrack.
“Today we are proud to continue honouring that racing DNA by placing it at heart of the future of our brand. We are driven by passion and excellence.
“Formula 1 represents a cutting-edge laboratory for the future electrification of our range, fully coherent with our vision for the coming years.
“Furthermore, motorsport brings the incomparable global exposure we wish to leverage for a successful future.”
The Italian marque has a long history in the world championship, Giuseppe Farina winning the 1950 title on a 158, and Juan Manuel Fangio the following year on a 159.
With the exception of the Indianapolis 500, which counted towards the world championship from 1950 to 1960, the Alfa Romeo 158 won every race of the 1950 season.
It claimed victory in 10 of the first 15 world championship events, with Ferrari (courtesy of Jose Froilan Gonzalez and Alberto Ascari) the only other marque to best it in events it entered.
In the decades since the marque has come and gone as a factory team and engine supplier, with the current arrangement little more than a commercial deal taking naming rights of what remains Sauber.