Pseudacris regilla, commonly known as the Pacific tree frog or Pacific chorus frog, is native to the western regions of North America. Its geographical range extends from British Columbia in Canada, through the western United States, including Washington, Oregon, and California, and reaches Baja California in Mexico.

The Pacific tree frog is highly adaptable and can be found in a wide variety of habitats. These include temperate forests, grasslands, chaparral, and even urban areas. It is commonly associated with moist environments and can be found near bodies of water such as ponds, lakes, marshes, and streams, particularly during the breeding season. However, it is also known to occupy dry areas when not breeding.

Pseudacris regilla occupies an ecological niche as both a predator and prey species. It plays a role in controlling insect populations as it primarily feeds on arthropods, including a variety of insects and spiders. The frog itself is preyed upon by birds, snakes, and larger mammals. This species exhibits notable adaptability, which is evident in its capacity to thrive in diverse environmental conditions and its morphological variations that may occur in different regions, aiding its survival in various habitats.