Is Bleach episode 296 filler?
Canon No, episode 296 of Bleach is canon.
#296
The Shocking Truth...The Mysterious Power Within Ichigo!
衝撃の真実…一護に秘められた力!
Aired 9 Nov 2010
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.