Felipe Nasr will make his Formula 1 race debut next year having been confirmed at Sauber alongside Marcus Ericsson.
The 22-year-old Brazilian was the test and reserve driver for the Williams F1 Team this season, where he has made four appearances in Friday practice sessions.
Nasr's appointment completes an all new driver line up for the Swiss squad following the team's move to sign former Caterham driver Ericsson last weekend.
The pair will replace the current pairing of German Adrian Sutil and Mexican Esteban Gutierrez.
Despite his relative inexperience behind the wheel of an F1 car, Nasr boasts impressive career to date having won the British Formula 3 championship, while currently sitting in the runner-up spot behind champion Jolyon Palmer in GP2.
“It is a very important step in my career to sign with the Sauber F1 Team for the 2015 Formula One World Championship,” said Nasr.
“This is an unforgettable moment that I owe to all of those who have supported me – my family, my friends, my sponsors, my teams and my country. Today the dream has come true.
“Sauber was responsible for the arrival in F1 of great names such as Felipe Massa, Kimi Raikkonen, Robert Kubica and Sebastian Vettel.
“I am proud now to also be part of this racing family. I had a wonderful year at Williams Martini, where I learned a lot and prepared myself to be a race driver in Formula One.”
Sauber boss Monisha Kaltenborn has followed the Brazilian's career closely and believes he thoroughly warrants a promotion to a F1 race seat.
Nasr will also bring long term backers Banco do Brasil to the team.
“We have been following Felipe's career path for some time now, and he fully deserves his position in Formula One having had a very successful career in junior categories,” said Kaltenborn.
“We are happy that he will be driving for our team next year. This means that Brazil will have one more young and talented driver in the sport.
“Banco do Brasil has been an important partner for Felipe so far, and we are delighted that such a renowned company is continuing to support him during this important step. We look forward to this partnership.”