Line of Duty is a British BBC police procedural television series created by Jed Mercurio. The first series premiered on 26 June 2012 and became BBC Two's best-performing drama series in ten years with a consolidated audience of 4.1 million viewers. The second series broadcast began on 12 February 2014; its widespread public and critical acclaim, led to the BBC commissioning a further two series. The third series broadcast began on 24 March 2016, and the fourth on 26 March 2017 on BBC One. The fifth series was completed at the end of 2018 and broadcast began on BBC One on 31 March 2019. The BBC has ordered a sixth series.
It is the most popular drama series broadcast on BBC Two in the multi-channel era and is a winner of the Royal Television Society Award and Broadcasting Press Guild Award for Best Drama Series. Line of Duty was included in a list of the Top 50 BBC Two shows of all-time and in a list of the 80 best BBC shows of all time. It was the highest-ranked current series in a list of the best police shows of all time and third in a poll of the best British crime dramas of all time.