Green brings nearly 15 years of senior-level industry experience to the role, having previously worked as managing director at Invnt, and director of group events at Barclays. She has also set up her own agency, Brand Communications and Events.
Thomas has spent the last 20 years at agencies such as Fold 7, Lowe, Pentland and Cheil, where he worked across brands such as BMW, Range Rover, Coca-Cola, Microsoft, Pepsi, Nike, Hugo Boss and Xbox.
Thompson, who joined Jack Morton in 2013, has been promoted from the role of associate creative director. During his time at the agency he has worked with clients such as Wella and Samsung.
Elswhere, Thompson has delivered projects for brands such as Freshfields Bruckhaus Deringer, Jamie Oliver, Royal Bank of Scotland, Telefonica and Topshop.
Mike Kunheim, managing director, Jack Morton Worldwide, said: "Client relationships and brave creative are at the heart of everything we believe in at Jack Morton, so these key appointments are a great boon to us and our clients. We’re super excited to both inject fresh talent and to grow our talent from within as we drive forward in our vision to create extraordinary experiences."