Stephen will also become director general of The Association of Independent Financial Advisers (AIFA) and the Association of Finance Brokers (AFB).
Stephen has more than twenty five years' experience of the life and pensions market and intermediary distribution.
Most recently director of distribution development at Aviva UK Life, Stephen developed and launched the industry's first and largest financial adviser academy.
He also led Aviva's work around the Retail Distribution Review, regularly engaging with the regulator and policy makers. Stephen previously worked for Prudential, Standard Life and a wide range of leading financial services companies during his time as a management consultant.
Stephen is a member of the ABI's Distribution and Regulatory Committee, a Board member of IFA Promotions Ltd (IFAP) and Origo. He was also Chairman of the Leaders Summit Group in 2009.
Lord Deben, chairman of AIFA, AMI and AFB, said: "Stephen has an excellent understanding of the challenges and opportunities faced by advisers, including the tough economic climate and the ever changing regulatory agenda.
"His experience will be vital to promote and protect our members. In AIFA, the IFA profession has a strong, united organisation that stands up for their interests.
"Stephen is well placed to lead our work and build on the significant contribution made by Chris Cummings and his team.
"The advice sector continues to be dominated by the Retail Distribution Review, the Mortgage Market Review and wider regulatory architectural changes.
"But challenging though these initiatives are, we have a major opportunity to ensure the critical importance of our profession is more widely understood.
"As the most trusted sector of the financial services industry, we must develop an even stronger voice for the intermediary profession in the UK and Europe."
Stephen Gay added: "There is a fantastic opportunity here to build on AIFA's successes and to take the organisation forward through this transformational period for the industry. I am delighted that I have been selected to lead AIFA, AMI and AFB.
"All three organisations are now firmly at the heart of political, regulatory and policy discussions. I look forward to representing members' interests at such a critical time."
A start date for Stephen is still being agreed.
