Based in Manchester, Griffiths had previously been acting editor, but her new remit covers hourly regional news bulletins as well as the half-hour 6pm weekday show.
The upcoming revamp of Granada Reports and Granada News has been overseen by controller of programmes Kieron Collins, who was keen to 'bring some fresh ideas to the news output', a Granada spokesman said.
The broadcaster has recently boosted its editorial team with the hire of a number of journalists in on-screen and off-screen roles.
Mark Alderton, now head of current affairs in the regional programming department, formerly held the news brief on Granada Reports too, but his role was split earlier this year.
In front of the cameras, Tony Morris replaces Tony Wilson, the Factory Records founder, as co-anchor with Lucy Meacock, the show's existing presenter.