St. Denis is an unincorporated community in Baltimore County in Central Maryland, United States, located in Arbutus, south of Baltimore.

It is located on the CSX main line between Halethorpe and Relay (the latter being the site of the Thomas Viaduct), and is best known as a stop on the MARC commuter rail (on the Camden line).

In former years, a station building stood here similar to that in Germantown, but all that remains are the platforms.

The Halethorpe MARC station is on a different line than the St. Denis station, as St. Denis is on the former Baltimore and Ohio Railroad, and Halethorpe on the former Pennsylvania Railroad.

This article about a location in Baltimore County, Maryland is a stub.