Oakland Mills High School was established in 1973 as one of the first high schools to serve the planned developed new U.S. town of Columbia, Maryland area, established by James Rouse and his Rouse Company in 1967 in Howard County, midway between Baltimore and Washington, D.C. It is part of the Howard County Public Schools system (HCPSS). The building had its first renovation in 1991, and another in 1998. A new addition was put onto OMHS in 2004, the "new wing," raising its total capacity to 1,400 students.