The HBO show, which has taken the top slot since 2012, was followed by "The Walking Dead" and "The Big Bang Theory" in the number two and three slots respectively, reported Aceshowbiz.
The fifth season finale of the medieval drama was illegally downloaded 14.4 million times, according to the piracy tracking site TorrentFreak.
The channel had actually taken actions to reduce piracy of the show this year by airing episodes of season five on the same date worldwide.
"Arrow" is the fourth most pirated show, while "The Flash" rounds out the top five.