Acorn School District or Acorn Public Schools was a school district headquartered in Acorn, an unincorporated area in Polk County, Arkansas, United States, about 5 miles (8.0 km) from Mena. Schools included Acorn Elementary School and Acorn High School. In addition to Acorn, it served a small section of Mena. The Ouachita River School District was established by the merger of the Acorn School District and the Oden School District on July 1, 2004.