Williams have hired Nicholas Latifi as their reserve driver for 2019, filling the gap left by Robert Kubica's promotion to the race team. Latifi was previously affiliated with Force India and tested for the team several times in the past year.
Canadian Latifi finished ninth in the Formula 2 championship in 2018, taking victory for DAMS in the Belgium sprint race and securing podiums in Azerbaijan and Russia.
His teammate Alexander Albon won four races and will drive for Toro Rosso in F1 next year.
Latifi will be at the controls for Williams in six FP1 sessions next year, as well as pre- and in-season and provide simulator support for Kubica and George Russell.
Latifi said: "I'm thrilled to be joining an iconic team like Williams as a Reserve Driver for 2019.
"It's a fantastic opportunity to continue my F1 development, and to build my on-track experience with more FP1 sessions and the rookie and Pirelli tests.
"As well as this, a big part of my role will be simulator driving and helping to support the development of the new car.
"I look forward to spending time in the factory at Grove, immersing myself within the team and assisting wherever I can. This is an amazing opportunity that I've been given and I'm excited to get started."