The consolidated ratings for Happy Valley show the series achieved an average audience of 7.2m.
7.8m tuned in to the final episode of the drama, which is made by the MediaCityUK-based Red Production Company.
Created, written and executive produced by Sally Wainwright for BBC One, the show has also been a hit with the iPlayer, with 8.1m requests for the show to date.
“Sally Wainwright’s sensational series has gripped the nation for the last six weeks. Visceral, emotional and provocative from beginning to end, it’s been fantastic to see our audience on tenterhooks, begging for more. The series is testimony to the creative ambition, quality and breadth of original British drama on BBC One,” said Charlotte Moore, controller, BBC One.