F1 veteran Bell's official job title will be executive director – technical, which means he will oversee the technical, engineering and performance functions of the Silverstone squad, reporting directly to team principal Mike Krack.
Bell's appointment further shores up Aston's technical department, led by technical director Dan Fallows, as it aims to go toe-to-toe with the likes of Ferrari and Mercedes on a more regular basis following a big step forward in 2023.
Bell's Alpine departure was announced on Wednesday morning, following the exit of technical director Matt Harman and chief of aerodynamics Dirk de Beer, although it is not thought to be connected to the squad's technical reshuffle.
"I have been impressed by the progress Aston Martin has made in recent years," Bell said on his appointment.
"The opportunity to play my part in that journey is incredibly exciting and I look forward to working with the great technical leaders at Silverstone.
"The scale and ambition of this project is highly motivating. I am a racer, and I see the hunger and determination powering this team. I look forward to playing my part with Mike and the rest of the team."
Krack commented: "I am delighted to welcome Bob Bell to Aston Martin. This is a key appointment to ensure we are optimising everything we do as a team and focusing on the right performance areas.
"Bob’s track record in the sport speaks for itself and his experience will help us continue to make steps forward on the exciting journey we are on."
Bell has been a highly-respected paddock figure for over four decades since joining McLaren as an aerodynamicist.
The now 65-year-old from Belfast went on to join the Enstone squad in 1997 in its Benetton days, returning to Renault following a spell at Jordan, acting as the team's technical director in its championship winning years with Fernando Alonso.
He left Renault again for stints at Mercedes and Marussia, before joining a third time in 2016, taking up a more advisory role in recent years.