Is ONE PIECE episode 744 filler?
Canon No, episode 744 of ONE PIECE is canon.
#744
No Way Out! Admiral Fujitora's Ruthless Pursuit!
逃場無し 大将藤虎非情の追撃！
Aired 5 Jun 2016
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.