In what is a rare move by a council PRO into a CEO role, Williams will join in mid-May.
He joins as the council battles to rebuild its image after it was slammed for providing 'unacceptably poor services at a high cost' in a report by the Audit Commission - which threatened ministerial intervention - in September last year.
In Rossendale he will replace CEO James Gravenor, who was drafted in on an interim basis five months ago.
Williams said Gravenor had done 'an awful lot of work' to improve Rossendale. However, earlier this month the Commision said the situation remained 'fragile' and that the council faced 'a number of critical issues', although it didpraise 'positive steps' that Rossendale had taken.
Williams joined Bradford - where he has overseen a 20-strong marcoms team, plus around 20 staff at tourist information centres - three years ago from a role as strategic planning director at marketing services agency CWG.
During his time at Bradford he has overseen PR initiatives aimed at boosting Bradford's image after the riots during the summer of 2001.
He also oversaw PR for the city's bid to secure European Capital of Culture status for 2008 which, though unsuccessful, Williams insisted had engendered a 'pulling together' of groups and organisations, giving a boost to civic pride.
Other PR initiatives have included the setting up of a Bradford 'Embassy' in London, and distribution of 100,000 'Wear a Badge for Bradford' badges.
'There's definitely been a mood change but there's lots more still to do,' Williams said, adding a recruitment hunt for his replacement was likely to begin within a couple of weeks.