The Mattawoman (also known as Mattawomen) were a group of Native Americans living along the Western Shore of Maryland on the Chesapeake Bay at the time of English colonization. They lived along Mattawoman Creek in present-day Charles County, Maryland. They were also recorded in the early 17th century by explorer John Smith at Quantico Creek in Prince William County, Virginia. He called them Pamacocack.
One of the Algonquian-language coastal tribes, the Mattawomen survived in the Chesapeake Bay area until 1735. They were under the loose domination of the paramount chiefdom of the Piscataway, also an Algonquian-language tribe.