County · code 24005
Baltimore CountyMaryland
Baltimore County is a county in Maryland with its seat in Towson, formed in 1659.
- Founded1659
- County seatTowson
- Named forCecil Calvert, 2nd Baron Baltimore
- Land area598 sq mi + 83 sq mi water
- Population854,535 2020 Census
- Parcels mapped374,966 checked 15 October 2026
Where it is
Baltimore on the map of Maryland
Maryland has 24 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Founded in 1659
An old deed may name a county that no longer exists, or a boundary that has since moved.
Baltimore County was created in 1659 from Anne Arundel, Kent, and non-county area. It was named after Cecil Calvert, 2nd Baron Baltimore. The county lost territory through the creation of adjacent counties including Cecil in 1674, Harford in 1774, and Carroll in 1836, and through the separation of Baltimore City as an independent city beginning in 1851.
- 1660Baltimore County created By 12 January 1659/1660, Baltimore was created from Anne Arundel, Kent, and Non-County Area 1 between Anne Arundel and Kent. Baltimore territorial limits, if any, are unknown and boundaries are estimated. · Archives of Md., 1:381
- 1698Exchanged territory Baltimore exchanged with Anne Arundel. · Archives of Md., 22:147
- 1727
- 1750
- 1774
Show all 10 changes
- 1660Baltimore County created By 12 January 1659/1660, Baltimore was created from Anne Arundel, Kent, and Non-County Area 1 between Anne Arundel and Kent. Baltimore territorial limits, if any, are unknown and boundaries are estimated. · Archives of Md., 1:381
- 1674Lost territory By 6 June 1674, Baltimore lost to creation of Cecil. Boundary between Baltimore and Anne Arundel was redefined (no change). · Archives of Md., 15:38-39
- 1698Exchanged territory Baltimore exchanged with Anne Arundel. · Archives of Md., 22:147
- 1727
- 1750
- 1774
- 1836Lost territory Baltimore lost to creation of Carroll. · Md. Laws 1835, ch. 256, sec. 1; Md. Laws 1836, ch. 19
- 1851Lost territory Baltimore lost to creation of the independent city of Baltimore City, which was separate from Baltimore County. · Md. Laws 1838, ch. 22, secs. 1, 4; Swindler, 4:413
- 1888Lost territory Baltimore lost to Baltimore City (Ind. City). · Md. Laws 1888, ch. 98, secs. 1-4/pp. 113-117
- 1918Lost territory Baltimore lost to Baltimore City (Ind. City). · Md. Laws 1918, ch. 82, sec. 1/p. 135
Land and parcels
What the maps cover in Baltimore
Who publishes each layer, how good it is, and when we last checked.
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Parcels Good enough
Lot lines and tax-map numbers for 374,966 parcels from Baltimore County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 15 October 2026 -
Address points Missing
No public address points layer found for Baltimore County yet.
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Buildings Reference
Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026
- Official
- from the office that keeps the record
- Good enough
- a reliable statewide or national copy
- Fallback
- a guide only; check the official record
- Missing
- nothing public found yet
People and land
Baltimore by the Census
Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.
Rules and offices
Baltimore County's official site
We have found the county's site but not its offices yet; start there.
County government
- County government
The official website of Baltimore County.
See your own lot on these maps
Open Baltimore County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.
Questions
Common questions about Baltimore County
- When was Baltimore County founded?
- Baltimore County was founded in 1659, and named after Cecil Calvert, 2nd Baron Baltimore.
- What is the county seat of Baltimore County?
- The county seat of Baltimore County is Towson.
- Is there an online parcel map for Baltimore County?
- Yes. Baltimore County publishes a parcel map of 374,966 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Baltimore County's boundary or name changed?
- Baltimore County was created in 1660. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Anne Arundel County, Carroll County and Frederick County.
- Is my lot in a flood zone?
- We do not have flood maps for Baltimore County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby