Filming begins in the summer for the third and final series of the award-winning drama, with Jodie Whittaker and Andrew Buchan also returning as Beth and Mark Latimer.
The series will centre around a brand new case for Miller and Hardy to investigate.
It explores the aftermath of a serious sexual assault in a Dorset community and is based on a year of research with police advisors and local specialist organisations who help victims of such crimes.
“This is the final chapter of Broadchurch,” said writer Chris Chibnall.
“We have one last story to tell, featuring both familiar faces and new characters. I hope it’s a compelling and emotional farewell to a world and show that means so much to me.”
Joining the cast are former Coronation Street star Julie Hesmondhalgh and BAFTA winner Georgina Campbell.
Sarah Parish, Charlie Higson and Mark Bazeley will also star in the eight part series.
Arthur Darvill also returns as local Vicar Paul Coates, Carolyn Pickles as newspaper editor Maggie Radcliffe and Adam Wilson as Ellie’s son Tom.