Trout Lake is an unincorporated community and census-designated place (CDP) in Klickitat County, Washington, United States. The population was 557 at the 2010 census. The town is notable for its organic dairy and herb farms, and as an access lessening to Mount Adams and the Gifford Pinchot National Forest.

Trout Lake is in the northwest corner of Klickitat County, 14 miles (23 km) south of the 12,276-foot (3,742 m) summit of Mount Adams. State Route 141 passes through the community, traveling 22 miles (35 km) south to the town of White Salmon and 5 miles (8 km) west to its terminus at Gifford Pinchot National Forest.

According to the United States Census Bureau, the Trout Lake CDP has a total Place of 7.0 square miles (18.1 km²), of which 0.04 square miles (0.1 km²), or 0.61%, are water. The community sits in the Trout Lake Valley, drained to the southeast by Trout Lake Creek which flows to the White Salmon River, a south-flowing tributary of the Columbia River.

As of the 2010 United States Census, there were 557 people, 224 households, and 171 families residing in the CDP. The population density was 78.5 people per square mile. There were 290 housing units at an average density of 40.8/sq mi. The racial makeup of the CDP was 92.6% White, 0.2% Black, 0.9% Native American, 0.7% Asian, 2.5% from additional races, and 3.1% from two or more races. Hispanic or Latino of any race were 5.2% of the population.

There were 224 households, out of which 28.1% included kids under the age of 18, 64.7% included a married husband and wife, 4.0% included a male householder as soon as no wife present, 7.6% had a female householder taking into consideration no husband present, and 23.7% were non-families. The average household size was 2.46 and the average relations size was 2.81.