Sarah Lancashire will reprise her role as Sergeant Catherine Cawood
BBC announced the show will begin filming six new episodes in early 2022. James Norton and Siobhan Finneran will also return to their respective roles as Tommy Lee Royce and Clare Cartwright.
AMC are jumping on board as co-producers for AMC+, which will house the series for its US audience.
The new series will be the final instalment of the hugely popular show, written by Sally Wainwright.
“I’m delighted to find myself back in the world of Catherine Cawood and her family and colleagues for the final instalment of the Happy Valley trilogy," said Wainwright. "It’s been wonderful to see the lasting impact this series has had on audiences all over the world."
The plot will centre around Catherine as she discovers the body of a gangland victim in a drained reservoir. The following chain of events eventually lead back to murderer Royce.
'Happy Valley' debuted in 2014, following up with its second series in 2016. It has been lauded for its realism and seen as a fresh take on the masculine-heavy detective trope.
The show has won two BAFTAs for each series with Lancashire winning the leading actress award for the second season.
'Happy Valley' is set to air later in 2022.