Stoffel Vandoorne will join Aston Martin as a test and reserve driver for the 2023 Formula One season.
The Formula E champion will share duties along with F2 champion Felipe Drugovich, raising doubts over the future of Nico Hulkenberg.
German Hulkenberg, Aston Martin's current reserve driver, has been linked with a move to Haas.
Vandoorne, who made 41 Grand Prix starts or McLaren from 2016 to 2018, will continue driving for the DS Penske Formula E team for the 2022/23 season.
"It is incredibly exciting to be stepping into a reserve-driver role in Formula One – and I'm delighted to be doing it with Aston Martin,” said 30-year-old Belgian Vandoorne.
"I've watched with great interest how the team has developed and expanded operationally, and I know how incredibly determined it is to make progress in every area.
"Joining Fernando [Alonso], who I already know from my Formula One racing career, and Lance [Stroll], to help them develop and improve next year's car will be a terrific job.
"I'm really looking forward to the challenge – and reward – of working together with the whole organisation at Silverstone."