Red Bull's head of aerodynamics, Dan Fallows, will join Aston Martin as technical director.
Fallows has been at Red Bull since 2006. He was promoted to his current role in 2014, replacing Peter Prodromou.
Fallows will take a role at Aston Martin which is open following Andy Green's promotion to chief technical officer.
He will leave Red Bull as soon as his current contract expires. Red Bull's statement said until then Fallows "remains fully focused on building upon the positive start we have made to the 2021 season".
Red Bull has not confirmed a replacement for Fallows, although team boss Christian Horner said the team will likely promote from within.
"This move creates exciting internal progression opportunities as we look to the future and draw from the wealth of the wider team," he said.