Baltimore County is a county located in the northern part of the U.S. state of Maryland. In 2004, its population was estimated to be 763,181.blank">http://www.baltimorecountymd.gov/Agencies/economicdev/gateway/demographics/index.html#Pop. Its county seat is _Towson. The name of the county was derived from the barony of the Proprietor of the Maryland colony, Cæcilius Calvert, 2nd Baron Baltimore, in County Longford, Ireland. It should be noted that Baltimore County does not actually include the city of Baltimore, which left the county to become an independent city in 1851.

Baltimore County is primarily suburban in character. It forms part of the Baltimore-Washington Metroplex.