The 25-year-old Brit has joined the Grove-based team as its Official Young Driver, and alongside assisting the team with simulator work at the factory, he’ll drive the FW41 in this year’s young driver test.
"I am immensely proud to be joining Williams Martini Racing as their official young driver,” said Rowland, who finished third in last year’s FIA Formula 2 Championship, taking race wins in Monaco and Hungary.
“It’s a fantastic opportunity for me and I will be working as hard as I possibly can to help them develop the car this season.
"Williams is a British team with a fantastic heritage and history which has made it one of the most respected teams in the sport. It’s always been my ambition to get a role in Formula One and I’m very excited to be doing that with Williams. They have always given young drivers the opportunity to progress so it’s now up to me to make a good impression and further my development as a driver.
"Hopefully with my hard work in the simulator and test I can impress the team. It’s certainly going to be an exciting challenge ahead and I want to help Williams as the team continues to work to close the gap to the front of the grid in 2018."
Rowland has previously tested for both McLaren and Red Bull, and prior to joining Williams also served as a Development Driver for Renault – an attractive proposition for Deputy Team Principal Claire Williams.
“I am pleased we have secured the services of Oliver, who is a talented and highly regarded young driver,” she said.
“He has raced at many Formula One circuits, and his experience and knowledge will complement the team’s ongoing engineering work. His addition to Williams will further strengthen the team.”