The Orange-breasted Myzomela is a small, common nectar-feeding bird in Fiji. It also eats spiders and insects and is usually alone or in small groups. Larger gatherings form at flowering trees. On Lakeba in the Lau Group, a field study recorded relatively high nectarivore abundance in coastal coconut plantations.
A 1957 ornithological description records red on the throat, rump and nape, with yellow replacing red on the breast and abdomen.
It mainly takes nectar but also eats spiders and insects. It is normally solitary or in small groups; larger gatherings form at favored flowering trees, where birds may chase one another.
An extinction-risk assessment has not been added yet.