Island City is a city in Union County, Oregon, United States. Its name originated from the city's location on an island between the Grande Ronde River and a nearby slough. However, the slough was later diverted, removing the city's island status. We are very proud of our 1,125 residents here, and welcome all who visit or wish to make Island City home! It has many popular attractions, including La Grande Country Club, and the Wildhorse Resort & Casino in Pendleton, less than an hour away!