Severn is a census-designated place (CDP) in Anne Arundel County, Maryland, United States. According to the 2020 U.S. census, the population of Severn is 57,118, a 22.6% increase from 44,231 in 2010. The zip code is 21144.

Hanover is an unincorporated community in the Baltimore/Annapolis area in northwestern Anne Arundel County and eastern Howard County in the U.S. state of Maryland, located south of Baltimore.