Williams has signed Felipe Nasr as its test and reserve driver for the 2014 Formula 1 season.
The 21-year-old Brazilian will drive in five Friday practice sessions at grands prix as well as three official tests, including the current pre-season session in Bahrain, and will attend every race as part of his role.
"I'm really happy to be joining the Williams family," said Nasr.
"They have a great history in the sport and some of the greatest Brazilian drivers of all time have driven for the team, so it's an honour to join names such as Piquet, Senna and Massa.
"This is a fantastic opportunity for me to make the next step in my career and I can't wait to get behind the wheel of a Formula 1 car for the first time in Bahrain."
Nasr joins Williams after two years in GP2, in which he failed to win a race but was a title contender for most of 2013, ending up fourth in the standings.
He had previously won the 2011 British Formula 3 title, and finished third in the '12 Daytona 24 Hours with leading Grand-Am team Michael Shank Racing.
Several recent Williams test drivers - including Nico Hulkenberg and Valtteri Bottas - have made it onto the F1 grid via third driver roles at the team.
Founder Sir Frank Williams said he hoped Nasr might follow in their footsteps.
"Felipe has a strong track record of success in his career so far and we have been watching him closely for a while," said Williams.
"We have a track record at Williams of bringing through new talent and giving them a chance to show what they can do on the world's biggest stage.
"By driving in five FP1 sessions this season, Felipe will have the perfect chance to showcase his skills and I'm confident he will be a strong addition to our driver roster."
Nasr's compatriot Felipe Massa has moved from Ferrari to Williams this year, joining Bottas in the race line-up.
The team has also announced two major new Brazilian backers, revealing earlier this week that oil company Petrobras had returned to the Williams sponsor line-up and also confirming a deal with banking firm Banco do Brasil on Friday.