Baltimore County, Maryland

Baltimore County is a county in Maryland, United States, wrapping around Baltimore City on three
sides. It had a population of 854,535 at the 2020 census, an estimated 847,650 by 2025, and covers
681.98 square miles (1,766.3 km2) centred near 39°24′N 76°36′W.

Towson is the county seat; its postal code is 21204. Unlike most Maryland counties, Baltimore
County has no incorporated cities or towns of its own — every community on this page is an
unincorporated census-designated place (CDP) or informal neighborhood governed directly by the
county. It runs on Eastern Time. Its FIPS code is 24005.

Towns & Villages in Baltimore County

The Census Bureau recognizes roughly 60 named CDPs in Baltimore County, plus hundreds of smaller
informal neighborhoods with no census boundary of their own. The table below lists the 32 largest
CDPs by 2020 population, from Dundalk at the top to Kingsville. CDP stands for census designated
place — a statistical community with no local government, mayor, or town council.

Lutherville and Timonium share a single Census-recognized place, Lutherville-Timonium, listed
above under the two historic village names most residents still use for the north and south
halves; both use ZIP 21093. Milford Mill and Woodlawn are adjoining CDPs that both use ZIP 21207
and are often confused for one place on maps — they are distinct communities either side of
Windsor Mill Road.

ZIP Codes

• 21222 — Dundalk
• 21204 and 21286 — Towson (21286 covers Towson’s northeastern edge)
• 21228 — Catonsville
• 21221 — Essex
• 21207 — Gwynn Oak, Woodlawn, Milford Mill and Lochearn
• 21117 — Owings Mills and Garrison
• 21208 — Pikesville
• 21133 — Randallstown
• 21220 — Middle River and Bowleys Quarters
• 21234 — Parkville and Carney
• 21128 — Perry Hall and Honeygo
• 21136 — Reisterstown
• 21030 — Cockeysville
• 21227 — Halethorpe, Arbutus, Lansdowne and Baltimore Highlands
• 21237 — Rosedale
• 21236 — Nottingham and Rossville
• 21093 — Lutherville and Timonium
• 21162 — White Marsh
• 21219 — Sparrows Point and Edgemere
• 21087 — Kingsville

Hampton has no ZIP of its own; mail there is delivered under the neighboring Towson code, 21286.
The county carries 51 ZIP codes in total once PO-box-only and single-entity codes are counted, most
of them covering rural communities along its northern edge such as Parkton, Monkton, Hydes and
Upperco.

Geography

Baltimore County forms a wide crescent around Baltimore City, running from the Pennsylvania
line in the north to the tidal shore of the Patapsco River and Chesapeake Bay in the south. Of its
681.98 square miles, 598 are land and about 83 are water — roughly 12 percent, driven by its
long shoreline along the Patapsco, Back River, Middle River and Gunpowder River, all Chesapeake
tributaries. The northern third of the county sits in the rolling Piedmont plateau, rising to
low hills near Hereford; the southern third along the Patapsco is flat coastal plain and was the
county’s industrial heartland.

Harford County lies to the northeast, Carroll County to the west, Howard County and Anne Arundel
County to the southwest and south, and York County, Pennsylvania, directly to the north. Baltimore
City sits entirely within the county’s southern boundary but is a separate, independent
jurisdiction with no county government of its own. Harford County, Carroll County, Howard County, Anne Arundel County and York County all border Baltimore
County directly; Baltimore City does not yet have its own page on this site.

Demographics

Baltimore County had a population of 854,535 at the 2020 census, Maryland’s third-highest county
count, and the latest estimate puts the county at 847,650 residents, a slight decrease. Dundalk and
Towson are by far the two largest communities, together holding roughly 15 percent of the county’s
population. Median household income runs $91,768, somewhat below Maryland’s statewide figure of
$98,678. Population density works out to about 1,430 people per square mile of land, among the
densest counties in Maryland outside Baltimore City itself, reflecting the county’s position
immediately around the city.

Economy & Local Life

Health care and social assistance employs the most workers in the county, about 69,911 people,
followed by educational services at 48,688 and retail trade at 43,271. Four universities anchor
that education employment: Towson University, University of Maryland, Baltimore County (in
Catonsville), Goucher College (Towson) and Stevenson University (Owings Mills). The former
Bethlehem Steel plant at Sparrows Point, once the largest steel mill in the world with about 30,000
workers at its mid-1950s peak, closed as a steelmaker in 2012; the 3,100-acre site is now Tradepoint
Atlantic, a logistics and manufacturing hub leasing space to Amazon, Under Armour and Volkswagen.
Owings Mills and Hunt Valley host large office and retail corridors, and the county fairgrounds in
Cockeysville hosts the Maryland State Fair each August & September, the county’s biggest annual
event.

History

Maryland’s colonial assembly formed Baltimore County on 30 June 1659, one of the province’s
original counties, named for Cecil Calvert, the second Baron Baltimore, whose title in turn came
from the Irish town of Baltimore in County Cork. The county seat moved from Joppa to Baltimore Town
in 1768. When the growing city of Baltimore was carved out as its own independent jurisdiction on
4 July 1851, the county lost its historic seat and voters chose Towson as the new county seat on
13 February 1854.

On 12 September 1814, American militia met a British invasion force at the Battle of North Point,
in the county’s Patapsco Neck peninsula. British Major General Robert Ross was killed early in the
fighting, and the delay the battle imposed on the British advance gave Fort McHenry’s defenders time
to prepare for the bombardment that inspired Francis Scott Key to write “The Star-Spangled
Banner” two days later. The date is still marked as Defenders Day in Maryland.

Getting There

Interstate 695, the Baltimore Beltway, rings the city and passes through the county’s southern
half; I-95, I-83, I-795 and I-895 all cross the county, and I-70 clips its western corner near
Woodlawn.

• Baltimore — adjoining, entirely surrounded by the county on three sides
• Towson — the county seat itself, about 8 miles north of downtown Baltimore
• Annapolis — about 25 miles south
• Bel Air — about 20 miles northeast

Baltimore/Washington International Thurgood Marshall Airport, about 15 miles south of Towson in
neighboring Anne Arundel County, is the nearest major commercial airport; Martin State Airport in
Middle River handles general aviation and Maryland Air National Guard operations. MARC commuter
trains stop within the county at Halethorpe and St. Denis on the Penn/Camden lines, connecting to
downtown Baltimore and Washington, D.C.

Frequently Asked Questions

Where is Baltimore County located?
It wraps around Baltimore City on three sides in central Maryland, bordered by Harford, Carroll,
Howard and Anne Arundel counties and York County, Pennsylvania.

What is the population of Baltimore County?
854,535 at the 2020 census, with a 2025 estimate near 847,650.

How big is Baltimore County?
681.98 square miles (1,766.3 km2), of which 598 square miles are land.

What is the county seat of Baltimore County?
Towson, chosen in 1854 after the city of Baltimore split off as its own jurisdiction, is the county
seat.

Does Baltimore County have any incorporated towns?
No. Every community in the county, including Towson and Dundalk, is an unincorporated
census-designated place with no town council or mayor of its own; the county government runs all
local services directly.

What ZIP codes does Baltimore County use?
51 in total, led by 21222 (Dundalk), 21204/21286 (Towson), 21228 (Catonsville) and 21221 (Essex).

What is Baltimore County known for?
The former Bethlehem Steel mill at Sparrows Point, once the world’s largest steel plant, and the
1814 Battle of North Point, which helped save Baltimore from British capture during the War of
1812.

More counties in this state: Towns and villages in Maryland.