Stephen Amell Oliver Queen, Green Arrow Actor David Ramsey John Diggle, Spartan Actor Emily Bett Rickards Felicity Smoak, Overwatch Actor Echo Kellum Curtis Holt, Mister Terrific Actor Rick Gonzalez Rene Ramirez, Wild Dog Actor Juliana Harkavy Dinah Drake, Black Canary Actor Katie Cassidy Laurel Lance, Black Siren Actor Colton Haynes Roy Harper, Arsenal Actor Kirk Acevedo Ricardo Diaz Actor Sea Shimooka Emiko Queen Actor LaMonica Garrett The Monitor Guest Star Katherine McNamara Mia Guest Star Ben Lewis William Guest Star Greg Berlanti Executive Producer Marc Guggenheim Executive Producer Andrew Kreisberg Executive Producer David Nutter Executive Producer