Canadian actor Mike Rowe has been cast as villain Deadshot for episode 3 of Arrow, according to TV Guide.  The episode, which airs October 9th, may not be the only appearance for Deadshot in the series, according to the report. 

Deadshot is not the only Arrow villain that’s been revealed; Kelly Hu was announced as playing China White at Comic-Con (see "Kelly Hu to Paly DC Villain China White").