The IDM said the new position was part of its expansion plans, and Clark's joining was designed to raise the profile of the organisation. He will be working alongside current chairman Simon Hall to develop The IDM brand name.
Clark began his career in the above the line advertising sector, and has held senior roles at Wunderman, DMB&B Direct and BMP, where he helped set up its direct division, BMP Young Clark Craig.
He was also marketing director at WWAV Rapp Collins in the mid-nineties when the agency first formed. More recently, he was chairman of Clark McKay & Walpole.
Clark said the role would help create greater awareness of the IDM's work for the industry, and that he hoped to support the work of Derek Holder, managing director of The IDM.
Holder said: "One of the things I hope Jonathan will help us do is raise our profile. We are an education trust, a registered charity, and all profits are spent on our education programmes for students, universities and colleges where we've had some incredible successes."