Stephen Amell Oliver Queen Actor Katie Cassidy Laurel Lance Actor Willa Holland Thea Queen Actor Colton Haynes Roy Harper Actor David Ramsey John Diggle Actor Emily Bett Rickards Felicity Smoak Actor Manu Bennett Slade Wilson Actor Susanna Thompson Moira Queen Actor Paul Blackthorne Detective Quentin Lance Actor Alex Kingston Dinah Lance Guest Star Katrina Law Nyssa al Ghul Guest Star Caity Lotz Sara Lance , The Canary Guest Star Kevin Alejandro Sebastian Blood Guest Star Colin Salmon Walter Steele Guest Star Nicholas Lea Mark Francis Guest Star Greg Berlanti Executive Producer Marc Guggenheim Executive Producer Andrew Kreisberg Executive Producer David Nutter Executive Producer Wendey Stanzler Director Jake Coburn Writer