The 64-year-old Scotsman, who is leaving to "pursue other design projects", will be replaced by current creative design director Julian Thomson. He will continue to work with Jaguar as a design consultant, however.
“I have had an incredible career at Jaguar," Callum said. "One of my biggest highlights was creating the XF, because it represented the beginning of a new era, moving Jaguar from tradition to contemporary design. It was a significant turning point in our story.
"I came into this role with a mission to take Jaguar design back to where it deserved to be. It has taken 20 years, but I believe I have achieved what I set out to do. Given the strength of both our products and the design team, I feel that now is the right time to move on, both personally and professionally, and explore other design projects.
"Designing Jaguar cars was a lifelong dream for me, and I’m delighted to remain involved as a consultant for the brand. I have worked closely with Julian Thomson for 18 years; he is a hugely talented designer and absolutely the right person to lead Jaguar design into its next chapter.”
Callum began his career in the motor industry in 1979, designing car parts for Ford. After 11 years there, he left to join Tom Walkinshaw Design, during which period he was partially responsible for the styling of the Aston Martin DB7.
In 1999, Callum succeeded the late Geoff Lawson as Jaguar's director of design, initially also directing Aston Martin design at the same time. He was responsible for large parts of the DB9 and Vanquish designs, although the former was credited overall to Henrik Fisker.
The XK of 2006 was his first chance to put his stamp on Jaguar design, followed by the XF in 2008. The new era of Jaguar exterior and interiors was completed with the 2010 XJ. Callum has since gone on to oversee the design of the ill-fated C-X75, the XF Sportbrake, the F-Type, the XE, the F-Pace and the I-Pace to name a few.