Bhutan (B), China (mainland) (B), India (B), Myanmar (B), Nepal (E) (B), Thailand, Vietnam (B).
Vagrant to Bangladesh, Hong Kong (China).
North-eastern India (from Darjeeling, in West Bengal, east to Arunachal Pradesh and Nagaland), Bhutan, western and northern Myanmar, southern and south-eastern China and northern Vietnam; probably also north-eastern Bangladesh.
 
Population
Estimated population is unknown (2010).
Brown Bush Warbler (Locustella luteoventris) [XC110835]
by Frank Lambert from , China (song)
Brown Bush Warbler (Locustella luteoventris) [XC756954]
by id from , China (song)
Subspecies
No subspecies.
Part of a species complex that also includes Taiwan Grasshopper-warbler (Locustella alishanensis), Russet Bush-Warbler (Locustella mandelli), Benguet Grasshopper-warbler (Locustella seebohmi), Sunda Grasshopper-warbler (Locustella montis) and Timor Bush-Warbler (Locustella timorensis) and some or all are often treated as conspecific. Taxonomy of this group confusing. The relationship between Brown Bush-Warbler (Locustella luteoventris) and Russet Bush-Warbler (Locustella mandelli) overlooked by most authorities until recently, when vocal differences indicated existence of two separate species in north-eastern Indian Subcontinent. Birds from western Myanmar (Arakan Yomas) described as subspecies ticehursti, and subsequent specimens from southern China (Yunnan) and northern Thailand claimed to be of this form. However, the first two are now considered to be merely very dark juveniles, while Thai specimen is a dark Russet Bush-Warbler (Locustella mandelli), and this subspecies no longer regarded as valid.