Lake Ketchum is a census-designated place (CDP) in Snohomish County, Washington, United States.

As of the census[2] of 2000, there were 1,173 people, 406 households, and 310 families living in the CDP.

The population density was 377.4 people per square mile (145.7 people/km2).

There were 406 households, out of which 39.4% had children under the age of 18 living with them, 63.8% were married couples living together, 8.4% had a female householder with no husband present, and 23.6% were non-families.

17.7% of all households were made up of individuals, and 4.7% had someone living alone who was 65 years of age or older.