The Pacific temperate rain forests of North America are the largest temperate rain forest zone on the planet. The Pacific temperate rain forests lie on west-facing coastal mountains along the Pacific coast of North America — the Pacific Northwest — from Kodiak Island in Alaska through Canada to Northern California, and are part of the Nearctic ecozone. The Pacific temperate rain forests are characterized by a high amount of rainfall, in some areas more than 300 cm (120 inches) per year and moderate temperatures in both the summer and winter months (between 10-24°C).

These rain forests occur in a number of ecoregions, which vary in their species composition, but are predominantly of conifers, sometimes with an understory of broadleaf trees and shrubs. Pacific Temperate rain forests can be found in the Northern Pacific coastal forests, Queen Charlotte Islands, British Columbia mainland coastal forests, Central Pacific coastal forests, Central and Southern Cascades forests, Klamath-Siskiyou forests, and Northern California coastal forests ecoregions.

The forests in the north contain predominantly Sitka Spruce and Western Hemlock, while those in the coastal forests are home as well to Coast Redwood (Sequoia sempervirens), Coast Douglas-fir (Pseudotsuga menziesii), Western Redcedar and Shore Pine. Notably, the three tallest species of trees are found here. Dense growths of epiphytes and mosses cover the trees, and lush vegetation is present everywhere.