Brighton and Hove City Council chief executive Geoff Raw is quitting to become managing director of Be First, a new homes and jobs development company for the London Borough of Barking and Dagenham.
He will remain in post until May to support the council through its budget making and local elections.
He joined the council in 2010 as strategic director – place before becoming chief executive in 2015.
Mr Raw said: ‘Brighton and Hove is an amazing city with a global reputation for creativity, innovation and vibrancy.
‘It has been my privilege to serve the city and its communities for over 12 years, the last eight as the council's chief executive.
‘I'm very proud of what the council has achieved for its city over this time, despite wider economic challenges, budget constraints and a Covid pandemic.'
Council leader Phélim Mac Cafferty, said: ‘On behalf of the council I want to thank Geoff for his many years of service to the city.
‘His leadership has helped steer the organisation through truly unprecedented times including during the worst days of the pandemic and the hugely challenging budget.'
