Howard County is a county located in the central part of the U.S. state of Maryland, between Baltimore and Washington, D.C. It is considered part of the Baltimore-Washington Metropolitan Area. In 2010, its population was 287,085. Its county seat is Ellicott City. The center of population of Maryland is located on the county line between Howard County and Anne Arundel County, in the unincorporated town of Jessup.