Brewster is a city in Okanogan County, Washington, United States.

According to the United States Census Bureau, the city has a total area of 1.19 square miles (3.08 km2), all of it land.

The radio telescope located in Brewster is the northernmost of ten dishes comprising the Very Long Baseline Array.

There were 730 housing units at an average density of 613.4 per square mile (236.8/km2).

20.5% of all households were made up of individuals, and 10% had someone living alone who was 65 years of age or older.

There were 739 housing units at an average density of 617.1 per square mile (237.8/km2).

23.4% of all households were made up of individuals, and 14.8% had someone living alone who was 65 years of age or older.