Adamson will join the board with immediate effect having headed up the Blues commercial department for the past two years.
Chief executive Geoffrey King told the official site: "We have been delighted with Garry's achievements since he arrived at the club and the direction he has taken our marketing and sales operations. He has made real improvements in developing the club's commercial revenues and customer service levels. As we move towards the new stadium a range of exciting opportunities will exist which Garry and his team will focus on delivering.