The FCA is one of two bodies which will replace the Financial Services Authority next year. The other is the Prudential Regulatory Authority.
The FCA will be responsible for the conduct regulation of all retail and wholesale financial services firms.
Mr Griffith-Jones is currently chairman of KPMG where he has worked since 1975.
Prior to joining the FCA, he will join the FSA board in September as non-executive director and deputy chairman to oversee the creation of the new authority with FCA chief executive-designate Martin Wheatley.
Mr Griffith-Jones said: “Having worked in the financial world all my professional career, I know how important it is that consumers, investors and businesses have trust in the integrity of the UK’s financial services, industry and markets.
“I see the future role of the Financial Conduct Authority as key to rebuilding that trust, in particular through its increased focus on consumer protection and choice.”
Financial Secretary to the Treasury Mark Hoban said: “I am pleased with the appointment of John Griffith-Jones as chairman of the FCA. It will be a key role in the successful delivery of the Government’s plan for a new regulatory structure in the UK.
“He understands the challenges facing the financial services sector and this, together with his experience in both chairman and chief executive roles, will be very valuable as we move towards the creation of the FCA.”