Shadowhunters, also known as Shadowhunters: The Mortal Instruments, is an American supernatural drama television series developed by Ed Decter, based on the book series The Mortal Instruments written by Cassandra Clare. It premiered in North America on Freeform on January 12, 2016. Primarily filmed in Toronto, Ontario, Canada, the series follows Clary Fray (Katherine McNamara), who finds out on her eighteenth birthday that she is not who she thinks she is, but rather comes from a long line of Shadowhunters, human-angel hybrids who hunt down demons, and has to deal with the struggle of forbidden love.

It is the second adaptation of the novel series, after the 2013 film The Mortal Instruments: City of Bones, which, like the series, was produced by Constantin Film, and serves as a reboot. The debut season of Shadowhunters received mixed responses from critics. The pilot episode attracted the largest audience for Freeform in more than two years. The show received numerous award nominations, winning one GLAAD Award, six Teen Choice Awards and five People's Choice Awards.

In March 2016, the series was renewed for a second season of 20 episodes, which premiered on January 2, 2017. In August 2016, showrunner Ed Decter left the series over "creative differences". Todd Slavkin and Darren Swimmer were named as Decter's replacements. In April 2017, Freeform renewed the show for a third season of 20 episodes, which premiered on March 20, 2018. In June 2018, Freeform canceled the series after three seasons, but ordered two extra episodes to properly conclude the series' story; the second half of the third season premiered on February 25, 2019, with 12 episodes ordered. The two-part series finale aired on May 6, 2019.