Home > MD > St. Mary's County > Great Mills > Zip 20634

Zip Code 20634 — Great Mills, MD

20634 is a ZIP Code associated with Great Mills, MD, located within St. Mary's. The postal region supports an estimated population of 7,088 residents across Data Pending housing units, with a population density of 391.4 people per square mile.
WorldPlaceData database updated: October 2026

📍 View location on OpenStreetMap (38.245820, -76.494120)

Data MetricLocal Statistic
Postal / Zip Code20634
Primary CityGreat Mills
State / ProvinceMD
CountySt. Mary's
Total Population7,088
Median Household IncomeData Pending
Total Housing UnitsData Pending
Population Density391.4 people/sq mi
TimezoneAmerica/New_York

How 20634 Compares

MetricZIP 20634St. Mary's CountyMD State Average
Population7,088113,4806,205,597
Median IncomeData PendingN/AN/A
Population Density391.4 /sq mi----

Nearby ZIP Codes

ZIP CodeCityDistancePopulationMedian Income
Zip 20620Callaway1.8 mi1,115N/A
Zip 20667Park Hall3.3 mi150N/A
Zip 20653Lexington Park3.6 mi26,852N/A
Zip 20619California3.7 mi14,212N/A
Zip 20692Valley Lee4.4 mi505N/A

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →