He will be leaving the organisation, which he helped to set up, at the end of this year after 11 years.
Prior to his role at the IMA, he worked for the Treasury and for the British Embassy in Washington.
Mr Saunders said: “After 11 years in this role I feel it is time for me to move on. It has been a great privilege to work with a first-rate team at the IMA and I am very proud of what we have achieved together since the Association was set up in 2002.
“I know that my successor will be taking charge of an organisation in very good shape to meet the challenges of the coming years.”
Douglas Ferrans, chairman of the IMA , said: “I would like to thank Dick for his leadership and commitment to the investment management industry during his tenure as chief executive.
“He has been a driving force in developing a strong voice for our industry in recent years and has built a first class management team around him.”
A successor for the role has not yet been chosen.