John Shewell joins from the London Borough of Sutton where he was head of media.
Brighton and Hove is changing to a cabinet format in July. This, coupled with the recent change to a minority Conservative administration, will form a large part of Shewell's work.
Interim head of corporate comms Kevin Kingston said: 'It is a very delicate situation at the moment. It is very political. It will be a key focus for John to work with the new administration and communicate its decisions.'
Shewell is in charge of a team of 30, including a press team of six. He is also overseeing internal comms, creative services and a design, print and sign team.
He will also be responsible for editing Brighton and Hove's City News publication.
Shewell reports to the director of environmental services, Jenny Rowlands. He replaces Christopher Masters, who left nine months ago.