Mushroom Corner is an unincorporated community in Thurston County, Washington, United States. Mushroom Corner is located in the urban growth area of Lacey, along Interstate 5 North of Olympia, and is included in the Tanglewilde-Thompson Place Census-designated place (CDP) for Census purposes. The "corner" in Mushroom Corner is located at the intersection of Steilacoom Road SE and Marvin Road SE. Mushroom Corner is a solidly middle class residential area.
The "Mushroom" in "Mushroom Corner" refers to Ostrom's Mushroom Farm which occupies the East side of the intersection.
Coordinates: 47°02′49″N 122°45′49″W / 47.04694°N 122.76361°W