Mr Rathi is set to begin his five-year term at the helm of the regulator in October, on an annual salary of £455,000 and succeeding interim chief executive Christopher Woolard.
But who is the man who will lead the City watchdog for the next half a decade?
London Stock Exchange plc
Oxford-educated Mr Rathi is currently the chief executive of London Stock Exchange plc and a director of international development at its parent company the London Stock Exchange Group.
The incoming FCA boss has been at the LSE since 2014 and as a condition of his new appointment he will not be involved in any supervisory or enforcement decisions relating to the company until June 2021.
When Mr Rathi joins the regulator he will not be allowed to have any remaining interest in London Stock Exchange Group shares.
Mr Rathi has experience as a policy man, having joined London Stock Exchange after 11 years at HM Treasury.
During a career within government, which lasted more than a decade, the new watchdog boss was director of the financial services group at the Treasury where he led international legislative negotiations in the EU.
Before that he was head of the financial stability unit during the 2008 financial crisis and served as private secretary to Tony Blair and Gordon Brown during their time as prime ministers between 2005 to 2008.
Mr Rathi has already had close dealings with the FCA, having sat on its markets practitioner panel since 2015 and in July last year was appointed as its chairman.
He also sat on the regulator's practitioner panel alongside positions on the boards of LCH ltd, Turquoise Global Holdings ltd. and Unavista Ltd.
The FCA practitioner panels are independent statutory bodies that represent the interests of the financial services industry within the UK’s regulatory framework.
Panel members are recruited to represent both their own sector and the industry as a whole, rather than individual firms.