According to the BBC, 17.1 million people across the UK watched the finale over the course of 28 days.
Without including non-TV devices, the total viewing figure is 15.9 million, which still makes it the highest audience for a drama programme since current records began.
The finale, which aired on September 23, drew an average of 10.4 million viewers in the overnight ratings.
Charlotte Moore, Director of BBC Content said: ”Bodyguard continues to smash records and thrill new audiences everyday via the boxset.”