Lloyd takes on the role from Charles Randell, who stood down yesterday after four years as chair.
He will act as chair until HM Treasury appoints a permanent successor.
Lloyd joined the FCA board in April 2019 and has served as senior independent director, Chair of the Board Risk Committee and chair of the Oversight Committee.
Earlier this week, the FCA announced the appointment of new chairs to lead two of its most important panels.
Andy Mielczarek will be chair of the FCA Smaller Business Practitioner Panel and Helen Charlton will be chair of the Financial Services Consumer Panel.
They replace Marlene Shiels and Wanda Goldwag and both will take up their roles on 1 June 2022 for a three-year term.
The FCA said that the roles were filled following an open recruitment process.