Mr Tiner said that he will leave his post in July, after less than four years in the FSA's top job, in order to pursue a career in the private sector.
"The job has been immensely enjoyable," Mr Tiner said in a statement.
"[But] this seems to me to be the right time to pass on the baton, with the FSA set firmly on the road to more principles-based regulation."
However, he gave no hint as to where he will end up in his next job.
The FSA's chairman Callum McCarthy said that he was disappointed that Mr Tiner was leaving.
"John has made an enormous contribution to the health of the financial services industry," he commented.
"He has been a leader in developing international regulation through his work in Europe. Within the FSA, he has been invaluable in developing and leading a management structure with discipline and enthusiasm."