The chestnut-bellied tit (Sittiparus castaneoventris ) is a small passerine bird in the tit family Paridae that is endemic to Taiwan.
The chestnut-bellied tit was first described by the English ornithologist John Gould in 1863 and given the binomial name Parus castaneoventris. It was formerly considered as a subspecies of the varied tit but was promoted to species status after the publication of a phylogenetic study in 2014.
The species differs from the varied tit in having underparts of a deep chestnut colour.
