Plethodon cinereus, commonly known as the Eastern Red-backed Salamander, is native to the northeastern United States and southeastern Canada. Its geographical distribution includes regions ranging from North Carolina to Quebec, extending westward to Minnesota and reaching eastward to the Atlantic coast.

The Eastern Red-backed Salamander typically inhabits deciduous and mixed forests where it relies on moist microhabitats. These environments maintain high humidity levels and moderate temperatures, necessary for the salamander's skin respiration. The species often seeks shelter under logs, rocks, leaf litter, and other natural debris found on the forest floor.

Plethodon cinereus occupies an ecological niche as a terrestrial, lungless salamander that depends heavily on moist environments for cutaneous gas exchange. It is a nocturnal species that plays a role in controlling invertebrate populations by preying on various invertebrates like insects and spiders. Its presence is often an indicator of forest ecosystem health.