The Baltimore Steam Packet Company, nicknamed the Old Bay Line, was an American steamship line from 1840 to 1962 that provided overnight steamboat service on the Chesapeake Bay, primarily between Baltimore, Maryland, and Norfolk, Virginia. Called a "packet" for the mail packets carried on government mail contracts, the term in the 19th century came to mean a steamer line operating on a regular, fixed daily schedule between two or more cities. When it closed in 1962 after 122 years of existence, it was among the last surviving overnight steamship passenger services in the United States.