County · code 42091
Montgomery CountyPennsylvania
Montgomery County, Pennsylvania is a county formed in 1784 with its county seat in Norristown.
- Founded1784
- County seatNorristown
- Named forRichard Montgomery and Montgomeryshire, Wales
- Land area483 sq mi + 4.2 sq mi water
- Population856,553 2020 Census
- Parcels mapped309,713 checked 16 October 2026
Where it is
Montgomery on the map of Pennsylvania
Pennsylvania has 67 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1784 from Philadelphia County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Montgomery County was formed in 1784 from Philadelphia County, and named after Richard Montgomery and Montgomeryshire, Wales. Norristown is the county seat.
Deeds and plats from before 1784 for land now in Montgomery County may have been recorded in Philadelphia County.
- 1784Montgomery County created Montgomery created from Philadelphia. · Pa. Stat., ch. 1108, sec. 1/11:364
Land and parcels
What the maps cover in Montgomery
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 309,713 parcels from Montgomery County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 16 October 2026 -
Address points Missing
No public address points layer found for Montgomery 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
Montgomery 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
Montgomery 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 Montgomery County.
See your own lot on these maps
Open Montgomery 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 Montgomery County
- When was Montgomery County founded?
- Montgomery County was founded in 1784, formed from Philadelphia County, and named after Richard Montgomery and Montgomeryshire, Wales.
- What is the county seat of Montgomery County?
- The county seat of Montgomery County is Norristown.
- Is there an online parcel map for Montgomery County?
- Yes. Montgomery County publishes a parcel map of 309,713 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Montgomery County's boundary or name changed?
- Montgomery County was created in 1784 from Philadelphia County. The Atlas of Historical County Boundaries records no boundary change since.
- Is my lot in a flood zone?
- We do not have flood maps for Montgomery County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby