Mendon-Union High School was a public school in Mercer County, Ohio that mainly served an area that included the village of Mendon and Union Township. The school and the district were closed following the 1991-92 school year in a budgetary move and they were merged with the neighboring Parkway School District for 1992-93. Parts of the district were also merged into St. Marys City Schools and Spencerville Local Schools.The Mendon-Union Pirates wore blue and gold while competing in the Midwest Athletic Conference.The Mendon-Union K-12 building was demolished in 2006 to help the Parkway School District focus on building a K-12 building on one campus.