Marriottsville is an unincorporated community in Howard, Carroll and Baltimore counties, Maryland, United States.

Waverley slave plantation occupied a significant portion of the land which was known as the Howard District of Anne Arundel County.

[7] From 1965 to 1974, large tracts of Marriottsville once known as Alpha were purchased by land speculators anticipating development.

In 1977 County Executive Edward L. Cochran chose Marriottsville for a landfill site.

An expansion plan proposed by Charles I. Ecker was suspended after contamination of groundwater was reported, which brought public water extensions, followed by density increases approved by the Howard County Department of Planning and Zoning for land development.