Is ONE PIECE episode 35 filler?
Canon No, episode 35 of ONE PIECE is canon.
#35
Untold Past! Female Warrior Bellemere!
秘められた過去！女戦士ベルメール！
Aired 2 Aug 2000
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.