Lance Stroll will drive for Racing Point alongside Sergio Perez next year, completing the driver line-up for the 2019 Formula One season.
The team announced on Friday that the Canadian, whose father led a consortium to take over the team in August, had committed to a long-term deal with them following the end of his time with Williams.
Stroll was promoted to a full-time seat with Williams, having previously served as a development driver, in 2017. His debut campaign was highlighted by a third-place finish at the Azerbaijan Grand Prix that saw him become the youngest rookie to claim a podium at 18 years and 239 days.
He claimed 40 points but endured a disappointing second season, finishing 2018 a lowly 18th in the drivers' championship with just six points to his name.
The 20-year-old will look to rediscover more of his 2017 form with his new team, having – as expected – replaced Esteban Ocon, who is now without a seat after two years with Force India.
Stroll told their official website: "This is the beginning of an incredibly exciting journey in my Formula One career.
Racing Point Force India is delighted to announce that @lance_stroll will join the team for 2019 to race alongside Sergio Perez. Lance has pledged his commitment to the team as part of a long-term deal.
— Racing Point Force India F1 (@ForceIndiaF1) November 30, 2018
"I look forward to working alongside a successful team with a great culture. It's a new challenge and I am excited to embrace this new opportunity."
Team principal and CEO Otmar Szafnauer added: "I'm pleased that we can finally confirm Lance's arrival to race alongside Sergio next year. It gives us an exciting line-up with the perfect blend of youth, talent, and experience.
"Lance is only 20 and already has two years of Formula One experience under his belt, as well as a podium finish and a front row start. We see huge potential in Lance and believe we can create an environment in which he can flourish.
"Our team has enjoyed great success nurturing and developing young and talented drivers, and we are very excited to begin our journey with Lance.
"I would also like to take the opportunity to thank Esteban Ocon for his contribution to the team over the last two seasons and wish him well for the future."