Haydon is an active member of The Micropalaeontological Society, being a past Chairman and the current Industrial Liaison Officer. He has been keen to see financial support from industry come into micropalaeontology training and was instrumental in establishing the Micropalaeontological Society Educational Trust Fund.
Haydon is currently Vice President of the Geologists’ Association and President elect for 2014. He maintains his interests in local chalk geology by being Chairman of the Hertfordshire Geological Society and Geological Adviser to the Chiltern Society.