TV Guide is reporting that Canadian actor Michael Rowe will play the character role of Deadshot in the third episode, titled "The Lone Gunman."
"Deadshot doesn't speak much, so he has to have that physicality," says executive producer Marc Guggenheim. "And Michael certainly has that. He has that look." Right now, it only looks like a one-shot appearance for Deadshot but if all works well than we'll see Arrow and him crossing paths again.