Lexington is a city in Morrow County, Oregon, United States. The population was 238 at the 2010 census. It is part of the Pendleton–Hermiston Micropolitan Statistical Area.

Morrow County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 12,186. The county seat is Heppner. The county is named for one of its first settlers, Jackson L. Morrow, who was a member of the state legislature when the county was created. Half of the Umatilla Chemical Depot, which includes the Umatilla Chemical Agent Disposal Facility, and the Naval Weapons Systems Training Facility Boardman are located within the county. Morrow County is part of the Pendleton-Hermiston, OR, Micropolitan Statistical Area. It is located on the south side of the Columbia River and is included in the eight-county definition of Eastern Oregon.