Is ONE PIECE episode 236 filler?
Canon No, episode 236 of ONE PIECE is canon.
#236
Luffy vs. Usopp! Collision of Two Men's Pride!
ルフィＶＳウソップ！ぶつかる男の意地
Aired 19 Jun 2005
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.