FSA chief executive Hector Sants will step down in the summer after three years in the role.
Sants says he set out a three-year role at the organisation when he took over, and has decided to stick to his original timetable.
Lord Adair Turner, chairman of the FSA, says Sants played a pivotal role in reforming the FSA following the financial crisis.
He took over the role from John Tiner in summer 2007, having previously worked as managing director of institutional and wholesale markets at the FSA.
Lord Turner says: "Hector has given outstanding service and leadership through the turbulent last three years and has played a pivotal role in reforming the FSA into a truly effective organisation. He will leave behind an organisation with strong purpose and a clear strategy."
"I am very proud of the manner in which the FSA rose to the challenge of dealing with such unprecedented turbulence across global financial markets," adds Sants.
"Moreover, I believe the FSA candidly examined the failings in financial regulation that contributed to the onset of the crisis, learned the lessons and has gone on to reform itself into a much stronger and better equipped organisation."
The FSA's board says it will announce the selection process for Sants's successor in due course.
