Originally, Henslow's sparrow was found in both the central prairies of the United States and the coastal marshes of the Atlantic Coast (3) (7), in habitats including swamps, salt marshes, tallgrass prairies and meadows. However, following the decline of these native habitats, this species has moved into additional sites such as areas of cultivated grassland (3).
During the breeding season, Henslow’s sparrow generally favours tall, dense grassland (3) (7) (8) (9) with a thick litter layer in which to hide nests (3) (8), and can even be found on hayfields and reclaimed strip mine sites which have been planted with grasses (7) (9). Breeding habitats for this bird tend to be within large, flat and damp areas with few or no trees, although forbs are often present, and are used by Henslow’s sparrow as perches upon which to sing (3).
Over the winter, Henslow's sparrow is found in habitats relatively similar to those it breeds in, although they may be much smaller than its breeding sites (4) and do not require a thick litter layer or abundant standing dead plant material (4) (8). Henslow’s sparrow is also known to winter in dense cover within the pine savannah in the south of its range (5) (8) (9), often associating with longleaf pine (Pinus palustris) (4) (8). This species demonstrates a preference for recently burned areas on its wintering grounds (8), and dense grasslands and the edges of bogs are also suitable winter habitats for this bird (4).