Sunnyside is an unincorporated community in Umatilla County, Oregon, United States. It is located about three miles north of Milton-Freewater, at the intersection of Oregon Route 332, which is also known as the Sunnyside-Umapine Highway, and Oregon Route 339. Sunnyside was once a station on the Walla Walla Valley Railway, which served the local fruit orchards, and the site of a Nebraska Bridge Supply and Lumber Co. planing mill from 1958-1963. There was also an Inland Fir Company sawmill.
Coordinates: 45°57′44″N 118°24′08″W / 45.962357°N 118.402189°W