Cowell has been moved from his current leadership role, as BBC Sport revealed on Saturday, following disagreements between the two over the running of the team and design of the 2026 car, according to insiders.
The statement added that Newey, who joined Aston Martin as managing technical partner in March, would be guiding the technical team, including the trackside operations of the car.
The move has come about through the realisation that Newey’s expertise and long experience – having won 12 drivers’ and 13 constructors’ championships with Williams, McLaren and Red Bull – make him the de facto authority in the team.
In that case, making him team principal is a logical step and Newey will be Aston Martin’s fourth team principal in four years, following Otmar Szafnauer, Mike Krack and Cowell.
Team owner Lawrence Stroll said in a statement: “Andy Cowell has been a great leader this year. He’s focused on building a world-class team and getting them to work well together, as well as fostering a culture that puts the race car back at the heart of what we do.
“This leadership change is a mutual decision we have reached in the interest of the team. We all look forward to continuing working with him in his new capacity.”
Stroll added that Newey’s new position would “enable him to make full use of his creative and technical expertise”.
Newey said: “Over the last nine months, I have seen great individual talent within our team.
“I’m looking forward to taking on this additional role as we put ourselves in the best possible position to compete in 2026, where we will face an entirely new position with Aston Martin now a works team, combined with the considerable challenge faced by the new regulations.
“Andy’s new role, focusing on the integration of the new power-unit with our three key partners, will be pivotal in this journey.”
Stroll had been considering a change of leadership for some time, and had approached a number of senior F1 figures, including former McLaren and Sauber boss Andreas Seidl, current head of the Audi F1 project Mattia Binotto and his former CEO Martin Whitmarsh.
Former Red Bull team principal Christian Horner has also been pushing for a role at Aston Martin, and wants a shareholding.
Sources at the team say Horner, who is free to work for another team from next summer after being sacked by Red Bull in July, will not be given a role at Aston Martin.
However, Newey is said to have given his former Red Bull colleague a tour of the Aston Martin factory under cover of darkness on Tuesday night.
The statement said Cowell, a former Mercedes F1 engine boss, had “implemented the much-needed structural changes to support the transition to a full works team in readiness for the new regulations in 2026”.
Cowell said in the statement that “having set the foundations” for Newey, it was “an appropriate time for me to take a different role”.