Katherine Evelyn Anita Cassidy (born November 25, 1986) is an American actress and director.
Following several minor television roles, she came to attention as a scream queen after starring in the horror films When a Stranger Calls (2006), as Kelli Presley in Black Christmas (2006) and as Ruby in the third season of the horror series Supernatural (2007–08). Following a supporting role in the action film Taken (2008), Cassidy played leading roles in the mystery horror series Harper’s Island (2009) and the remake of the drama series Melrose Place (2009–10). She starred as Kris Fowles in the slasher film remake A Nightmare on Elm Street (2010) and had a recurring role as Juliet Sharp during the fourth season of the teen drama Gossip Girl (2010–12).
Cassidy had her breakthrough in 2012, after being cast as Laurel Lance / Black Canary, on The CW television series Arrow. Cassidy has reprised her role in the Arrowverse series The Flash and Legends of Tomorrow as well as voicing the character in the animated web series Vixen. Following her character’s death in season 4 of Arrow, Cassidy began playing Laurel Lance / Black Siren, an antagonistic version of the character from a parallel universe, originating on The Flash and continuing on to Arrow.
In June 2010, The CW announced Cassidy would have a major recurring arc in the fourth season of the teen drama series Gossip Girl. Cassidy portrayed Juliet Sharp, who attends Columbia University and sets out to ruin the life of the show’s central character Serena van der Woodsen. Cassidy made her first appearance in the season premiere and went on to appear in over 11 episodes of the season.
In May 2012, Cassidy was cast as the title character in the film adaptation of the graphic novel The Scribbler, alongside Eliza Dushku, Michelle Trachtenberg and Gina Gershon. She plays Suki, a young woman with dissociative identity disorder.
In March 2011, Cassidy was cast in the ABC drama pilot Georgetown as Nikki, a smart and quick-witted junior staffer in the White House Communications Office with connections to the First Lady. The pilot was created by Gossip Girl executive producers Josh Schwartz and Stephanie Savage. The series was not picked up by ABC.
In February 2012, Cassidy landed the main cast role of Laurel Lance / Black Canary in The CW’s series Arrow, which is based on the Green Arrow comic books. The series premiered on October 10, 2012. Cassidy left the show as a series regular after her character was killed off in episode 18 of the fourth season on April 6, 2016. On May 17, 2016, she guest-starred in the Arrowverse spin-off series The Flash for the second time, but as the metahuman Black Siren, Laurel’s Earth-2 doppelgänger, in the second-season episode “Invincible”. On July 23, 2016, it was announced that Cassidy had signed a deal with Warner Bros. to appear across multiple CW shows, including Arrow, The Flash, and Legends of Tomorrow. On March 27, 2017, it was announced that Cassidy would return to Arrow as a series regular season 6; reprising the role of Black Siren. She continued in that role for the remaining duration of the show. The season 8 episode “Leap of Faith” marked her directorial debut.
In 2016 Cassidy portrayed the character of Sharon (a character inspired by late fashion model and actress Sharon Tate) in the direct-to-digital-HD horror film Wolves at the Door, loosely based on the Manson Family’s murders.
Cassidy also stars in the 2017 PS4 game Hidden Agenda.