Menlo is a small unincorporated community in the Willapa Valley of Pacific County, Washington, United States.

The area was named for the California town of Menlo Park[2] in 1893 when the Northern Pacific Railway line was laid down through the Willapa Valley.

[4] Menlo is located within Census Tract 9504 of Pacific County, which has a population of 3,921 and covers a larger area than the Willapa Valley School District.

[5] This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F.

[6] The Willie Keil's Grave State Park Heritage Site is located approximately 2 miles (3.2 km) north of Menlo.