The Pacific Ocean borders the Pacific Northwest region, shaping its coastal climate and ecosystem.

The Pacific Ocean is the defining body of water that borders the Pacific Northwest region of the United States, which includes the states of Washington, Oregon, and Idaho. This ocean greatly influences the region's climate, bringing mild, wet winters and cool summers to coastal areas, as well as providing abundant marine life and resources. The ocean's proximity supports a significant fishing industry, particularly for salmon and other seafood. Coastal cities such as Seattle, Portland, and Vancouver (Canada) are major ports, contributing to the region’s economy and global trade.