Hackney Council's former housing director Michael Scorer will join Southwark as its strategic director of housing and modernisation in February, taking over from Gerri Scott.
Scorer has 22 years of experience working in the public sector and oversaw the development £80 million capital programme in Hackney.
The new council director said he was "humbled" by the opportunity. "I know I will have to work hard and build on the success that has already been achieved to continue to deliver Southwark's fairer future promises, including housing and neighbourhoods that enable our residents to thrive, and of which they can be proud.
"I'm looking forward to getting to know Southwark; the people who live here and the place, and to building strong relationships with people that enable us to work together for the benefit of all.
The appointment was welcomed by council leader, Peter John: "We are very pleased to have appointed Michael to the biggest housing job in London – managing the housing of London's biggest social landlord, delivering one of the most ambitious council house building programmes in the country, and helping the council to modernise its services for residents," he said.
"We've already surpassed one degree of global warming," said Kristen Buida, manager of the London Climate Change Partnership.