Nicoll is moving to become director of conduct policy overseeing the implementation of the retail distribution review, replacing Dan Waters, and both will take up their new roles at the start of October.
Adams joined the FSA in1998 from the Bank of England and has held a number of roles at the regulator including head of wholesale insurance firms.
He currently heads up the department that supervises the major retail UK banks and was also responsible for the implementation of the supervisory enhancement programme within his department.
Adams is a representative on the international Senior Supervisors’ Group and the Basel Committee Standards Implementation Group.
FSA retail managing director Jon Pain says: “I am delighted to announce this appointment today.
“Julian has been outstanding in dealing with some of the issues that the banking sector has faced in the last couple of years and has played a key role in implementing our more intensive supervision model for major firms.”