Niobium oxide may refer to:
- Niobium monoxide (niobium(II) oxide), NbO
- Niobium dioxide (niobium(IV) oxide), NbO2
- Niobium pentoxide (niobium(V) oxide), Nb2O5
In addition to the above, other distinct oxides exist
- general formula Nb3n+1O8n−2 where n ranges from 5 - 8 inclusive, e.g. Nb8O19 (Nb16O38).
- Nb12O29 and Nb47O116
Natural niobium oxide is sometimes known as niobia.