The Gray's Grasshopper Warbler, Locustella fasciolata, is an Old World warbler in the grass warbler genus Locustella. It breeds from western Siberia east to Sakhalin island, Japan and Korea. It is migratory, wintering in southeast Asia.

This small passerine bird is a species found in lowland and coastal regions, nesting in forests or thickets.

This is the largest of all the Locustella warblers, approaching the size of the Great Reed Warbler. The adult has an unstreaked olive-brown back, uniformly grey breast and buff underparts, with unmottled dull orange under tail-coverts.

The song is a short phrase, loud and distinctive, and nothing like the insect-like reeling of European Locustella species, and more musical than that of the Pallas's Grasshopper Warbler.