Katherine Evelyn Anita "Katie" Cassidy (born November 25, 1986) is an American actress. She portrays Laurel Lance/Black Canary in a lead role in the first four seasons of Arrow, and also special guest starred in season one of The Flash and in season one of DC's Legends of Tomorrow. She portrayed Earth Two equivalent Laurel Lance/Black Siren in a special guest starring role in season two of The Flash. She will also voice her character in a major role in season two of Vixen.
Cassidy signed a deal that would make her a series regular across all of the Berlanti shows (like Wentworth Miller). As of 2016, she has the freedom to move across season five of Arrow, season three of The Flash and season two of DC's Legends of Tomorrow.