Chondestes grammacus, commonly known as the Lark Sparrow, is native to North America. Its geographical distribution primarily includes parts of the United States, southern Canada, and northern Mexico. Within the United States, it is predominantly found in the Great Plains, the Midwest, and western regions extending to California.

The Lark Sparrow typically inhabits open habitats, such as grasslands, prairies, and savannas. It is also found in agricultural fields, open woodlands, and ranch lands. The species prefers environments with sparse ground cover and areas where shrubs or scattered trees are present, which provide perching sites and cover.

Lark Sparrows are ground-nesting birds and have an ecological niche as insectivores and granivores. They feed on seeds and insects, helping in seed dispersal and pest control. Their choice of habitat with open areas and sparse vegetation supports their foraging style, which involves walking and hopping on the ground to search for food. Additionally, regional adaptations may lead some populations to adjust slightly to more arid or modified agricultural landscapes.