Elkridge is an unincorporated community and census-designated place (CDP) in Howard County, Maryland, United States. The population was 15,593 at the 2010 census. Founded early in the 18th century, Elkridge is located at the confluence of three counties, the other two being Anne Arundel and Baltimore counties.
Elkridge qualifies as the oldest settlement in its present county, when Howard was a part of Anne Arundel County. Its location on the Patapsco River was a key element in its growth. The Maryland General Assembly elected a law to erect a 30-acre (120,000 m2), forty-lot town at the pre-existing settlement of Elkridge Landing to be called "Jansen Town" in 1733. In 1738 an attempt to formalize the town failed with the death of the commissioners before passage. In 1750 a second attempt to formalize the town was attempted around the lands of Phillip Hammond. By comparison, Baltimore Town consisted of only 25 dwellings at that time. A third petition was filed in 1762.
The settlement was founded as a place where planters, who each had a wharf along the river, could bring their tobacco crop to be loaded on English trading ships.