Captain Jack Harkness Actor To Join Cast of 'Arrow'.

SOURCE: 'Torchwood' star John Barrowman joins CW's 'Arrow'

We don't know who he is playing, save that he's a “well-dressed man” who is “as mysterious as he is wealthy" and that "he is an acquaintance of the Queen family and a prominent figure in Starling City.”

My guess? John DeLeon.