Bangladesh, Brunei Darussalam, Cambodia, China (mainland), India, Indonesia, Japan, Laos, Malaysia, Mongolia, Myanmar, Nepal, North Korea, Philippines, Russia (Asian) (B), Russia (Central Asian) (B), Russia (European) (B), Singapore, South Korea, Sri Lanka, Taiwan (China), Thailand, USA, Vietnam.
Vagrant to Belgium, Denmark, Finland, France, Germany, Hong Kong (China), Kazakhstan, Montenegro, Netherlands Antilles, Norway, Palau, Serbia, Svalbard and Jan Mayen Islands, Sweden, United Kingdom.
Population
Estimated population is unknown (2010).
Lanceolated Warbler (Locustella lanceolata) [XC381994]
by Per Alstr\u00f6m from , China (song)
Lanceolated Warbler (Locustella lanceolata) [XC339926]
by R. Martin from , Russian Federation (song)
Subspecies
DNA studies indicate that this species forms a group with Common Grasshopper-warbler (Locustella naevia), River Warbler (Locustella fluviatilis) and Savi's Warbler (Locustella luscinioides). Close affinities of these with certain Asian Bradypterus species is also suggested.
The following 2 subspecies are recognised:
lanceolata (Temminck, 1840) - Breeds southern Finland, Russia (Karelia, and from Perm and western Urals east to lower R Kolyma, southern Kamchatka and Sea of Okhotsk, and south to Altai, Amurland and Ussuriland), extreme northern Mongolia and north-eastern China (Manchuria). Non-breeding north-eastern Indian Subcontinent, south-eastern Asia and northern Philippines south to Sumatra and western Java.
hendersonii (Cassin, 1858) - Breeds Sakhalin I, southern Kurils and northern Japan (Hokkaido). Non-breeding south-eastern Asia.
BirdLife International Species Factsheet