Croydon LBC chief executive Katherine Kerswell has handed in her resignation five years after joining the council, The MJ understands.
A council spokesperson said there was no payoff beyond any contractual obligations.
Executive mayor of Croydon Jason Perry said: 'Having joined Croydon at an incredibly challenging time, she has led our workforce through a period of unprecedented and rapid change and improvement.
'The council has made significant progress during this time. Achievements include a good Ofsted, a good CQC, the lifting of the voluntary undertaking by the social housing regulator and an excellent Local Government Association corporate peer challenge.
'Katherine has worked tirelessly to support the improvements that residents expect and deserve, and her experience and expertise as a local government leader have been invaluable on our journey.'
The departure comes after commissioners were appointed despite protestations from the council's mayor Jason Perry and weeks after it was announced that Jane West was to leave her role as corporate director for resources and section 151 officer at Croydon.
Kerswell has overseen a stabilisation plan, which was called for by the Government after the borough received £136m exception financial support this financial year.
