Is Bleach episode 145 filler?
Canon No, episode 145 of Bleach is canon.
#145
The Espada Gather! Aizen's Royal Assembly
エスパーダ集結!藍染の御前会議
Aired 24 Oct 2007
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.