Red Bull has opted to confirm the appointment for Aston Martin by revealing Fallows will be leaving the team at the end of what will be his 16th season this year.
Fallows joined Red Bull in 2006 as team leader in the aerodynamics department, going on to be promoted to head of aerodynamics eight years later.
Confirming the move, Red Bull team principal Christian Horner said: “It goes without saying that Dan will be missed as he has played an important role during his time at Red Bull Racing and I would like to thank him for his contribution towards the Team’s successes.
"We do, however, recognise that the chance to take on the role of technical director within a Formula 1 team is an appealing next step in his career.
"In turn, this move creates exciting internal progression opportunities as we look to the future and draw from the wealth of talent within the wider team.”
Red Bull has stated Fallows will not be departing until the conclusion of his contract and that he "remains fully focused on building upon the positive start we have made to the 2021 season".
Horner, however, has intriguingly revealed that will not be for a couple of years.