Foulkes will work with Live Union's directors on a number of initiatives that will benefit the company's clients.
Foulkes joined The Imagination Group in 1983 and left in August 2012 as company director. In January 2013, he became vice chair for the Business Visits and Events Partnerships (BVEP).
Steve Eakins, Live Union’s managing director, said: "With the rapid growth of our business and our client portfolio it is important that we add strength to our offer, and we are delighted that Richard has agreed to be part of the team.
"Richard's experience in the content-driven global event sector is second to none. He has worked for some of the world's biggest brands on the world's largest events, he has always put strong content and creative thinking at the heart of event-based communications and this reflects our strategy, positioning and ambition for continued growth."
Foulkes said: "From my first contact with Live Union I was impressed not only by their energy and approach but by their attitude. They intuitively understand the changing role of events within communications, where the value lies for today's audiences, and how to harness all communication from digital to personal to give a whole new dimension to the delegate experience."
"This is an amazing period of innovation within events and I only want to work with companies who are at the forefront of this. I believe that events have never had so much potential to deliver delegate as well as organiser value, and clients need agencies that understand how to achieve this. Live Union’s understanding of new audience behaviours and new technologies gives them that ability."