The line-up was announced at a special press event in Milan, Italy on Saturday, where the team revealed further details of their new title sponsorship deal with Alfa Romeo, including a revised red and white livery concept for next season's auto and a new logo.
Formula Two champion Charles Leclerc will graduate to F1 with Sauber next season.
Saturday's event showed off a new red and white livery, with Alfa Romeo branding prominent on the engine cover, and a redesigned logo.
Meanwhile, Sweden's Marcus Ericcson stays in the lineup despite failing to score a point in 2017.
Despite the stronger links to Ferrari, the Italian manufacturer was unable to get its way, with Sauber confirming Leclerc and Ericsson at its launch on Saturday. Having used a year-old power unit this season, next year will see Sauber running the latest specification in a deal that has since been extended to the Alfa Romeo partnership.
The Monegasque driver steps up into Formula 1 as the 2017 FIA Formula 2 Champion, having become the first driver to win both that championship and the GP3 Series, which he did in 2016, and he moves up with the support of Scuderia Ferrari as part of their young driver programme.
"Formula One is the natural reference point for a marque like this", he said.
"It's an awesome opportunity for me but also for the team", said Ericsson, whose financial support has always been linked to Rausing and the Tetra Laval packaging group.
With Sauber teaming up with Alfa Romeo ahead of the 2018 championship, Leclerc was widely tipped to take one of the two Sauber race-seats.