Wasco is a city in Sherman County, Oregon, United States. The population was 410 at the 2010 census.

Sherman County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 1,870, making it the second-least populous county in Oregon after nearby Wheeler. The county seat is Moro, and the largest city is Wasco. The county is named for William Tecumseh Sherman, a Union general in the American Civil War.