Route 9 (Baltimore) (disambiguation)
Route 9 is a bus route operated by the Maryland Transit Administration in the suburbs of Baltimore. Route 9 may also refer to the following surface transit routes in the Baltimore Metropolitan Area:

 No. 9 Halethorpe Streetcar, 1900–1926, now Route 35 (MTA Maryland) bus service
Ellicott City Line, 1927 to 1957
Route 9 (Baltimore 1971-1973) to Fort Howard, part of Route 4 until 1993