Those Who Kill (Danish: Den som dræber) is a Danish crime TV series from 2011, which follows a fictitious unit within Copenhagen Police which specialises in investigating serial murders. The series was aired as five two-part stories in Denmark (i.e. ten episodes in total), but has aired as five feature-length episodes in most other countries. A separate 92 minutes feature film, Fortidens skygge, which forms a continuation and ending of the series, premiered in Danish cinemas on 15 March 2012, and is being aired as the final episode or episodes of the series in many other countries, such as the UK and Germany.

The series is created and written by Elsebeth Egholm and Stefan Jaworski, with various other screenwriters helping out as episode writers, among them Siv Rajendram, Rikke De Fine Licht and Morten Dragsted. Directors have been Birger Larsen, Niels Nørløv and Kasper Barfoed. The series is a Danish-German-Swedish-Norwegian co-production.

Although originally planned to run for several seasons, Danish TV2 announced in October 2011 that there would be no further seasons made, due to falling viewer shares after the first few episodes. TV2 programming manager Keld Reinicke stated that, "We have no plans to continue the series as it never gave us the audience share we expected in Denmark".

Announced in April 2018, Those Who Kill returned to the screens in 2019 on the Viaplay streaming service and the TV3 network across Scandinavia, with a new separate season which starred Kenneth M Christensen and Natalie Madueño.