The Baikal bush warbler, Baikal grasshopper-warbler or David's bush warbler (Locustella davidi) is a migratory species of Old World warbler in the family Locustellidae. It breeds from the southern part of the Russian Far East (including the Lake Baikal region) to northeast China (southern Heilungkiang south to southern Hopeh) and North Korea. It winters from southern China south to northern Thailand. Its breeding habitat is taiga forests, especially in clearings or at streams.