Warrenton is a small, coastal city in Clatsop County, Oregon, United States. Named for D.K. Warren, an early settler, the town is primarily …Warrenton is a small, coastal city in Clatsop County, Oregon, United States. Named for D.K. Warren, an early settler, the town is primarily a fishing and logging community. The population was 6,277 according to the 2020 US Census. Warrenton is a less urbanized area close to the Clatsop County seat, Astoria.