Pennsylvania Counties: Complete List of All 67 Counties

Pennsylvania has 67 counties, covering cities, boroughs, townships, and rural communities across the state. Each county has its own county seat and local government structure.

I’ve organized this guide to make the Pennsylvania counties easy to find and compare. You’ll find the complete county list, county seats, county classification, population facts, area information, county codes, and a few useful historical details.

Table of Contents

Quick Answer: How Many Counties Are in Pennsylvania?

There are 67 counties in Pennsylvania.

The state has counties ranging from large urban areas such as Philadelphia County and Allegheny County to small rural counties such as Cameron County and Forest County. Pennsylvania assigns each county a number from 1 to 67 for state administrative purposes.

Here are a few quick facts:

Total counties: 67
Largest county by land area: Lycoming County
Smallest county by land area: Montour County
Most populous county: Philadelphia County
Least populous county: Cameron County
Newest county: Lackawanna County
Oldest counties: Philadelphia, Bucks, and Chester

The counties were created over a long period. Some date back to the colonial period, while Lackawanna County was created in 1878.

Pennsylvania Counties Map

A Pennsylvania counties map is useful because the state has 67 separate county areas spread across a large geographic region.

The map also makes it easier to see how counties relate to major areas such as Philadelphia, Pittsburgh, the Poconos, the Allegheny Mountains, and the northern and western parts of the state.

When I use a county map as a reference, I find it easier to understand the state’s layout before looking at individual county information.

List of Pennsylvania Counties and County Seats

The table below lists all 67 Pennsylvania counties in alphabetical order with their county seats. County-seat information is based on current state records.

#	Pennsylvania County	County Seat
1	Adams County	Gettysburg
2	Allegheny County	Pittsburgh
3	Armstrong County	Kittanning
4	Beaver County	Beaver
5	Bedford County	Bedford
6	Berks County	Reading
7	Blair County	Hollidaysburg
8	Bradford County	Towanda
9	Bucks County	Doylestown
10	Butler County	Butler
11	Cambria County	Ebensburg
12	Cameron County	Emporium
13	Carbon County	Jim Thorpe
14	Centre County	Bellefonte
15	Chester County	West Chester
16	Clarion County	Clarion
17	Clearfield County	Clearfield
18	Clinton County	Lock Haven
19	Columbia County	Bloomsburg
20	Crawford County	Meadville
21	Cumberland County	Carlisle
22	Dauphin County	Harrisburg
23	Delaware County	Media
24	Elk County	Ridgway
25	Erie County	Erie
26	Fayette County	Uniontown
27	Forest County	Tionesta
28	Franklin County	Chambersburg
29	Fulton County	McConnellsburg
30	Greene County	Waynesburg
31	Huntingdon County	Huntingdon
32	Indiana County	Indiana
33	Jefferson County	Brookville
34	Juniata County	Mifflintown
35	Lackawanna County	Scranton
36	Lancaster County	Lancaster
37	Lawrence County	New Castle
38	Lebanon County	Lebanon
39	Lehigh County	Allentown
40	Luzerne County	Wilkes-Barre
41	Lycoming County	Williamsport
42	McKean County	Smethport
43	Mercer County	Mercer
44	Mifflin County	Lewistown
45	Monroe County	Stroudsburg
46	Montgomery County	Norristown
47	Montour County	Danville
48	Northampton County	Easton
49	Northumberland County	Sunbury
50	Perry County	New Bloomfield
51	Philadelphia County	Philadelphia
52	Pike County	Milford
53	Potter County	Coudersport
54	Schuylkill County	Pottsville
55	Snyder County	Middleburg
56	Somerset County	Somerset
57	Sullivan County	Laporte
58	Susquehanna County	Montrose
59	Tioga County	Wellsboro
60	Union County	Lewisburg
61	Venango County	Franklin
62	Warren County	Warren
63	Washington County	Washington
64	Wayne County	Honesdale
65	Westmoreland County	Greensburg
66	Wyoming County	Tunkhannock
67	York County	York

A county seat is the main administrative center of a county. It is often where the county courthouse and other county offices are located.

Pennsylvania Counties by Population

Population is one of the easiest ways to see how different Pennsylvania counties can be.

Philadelphia County is by far the most populous county. The July 1, 2025 population estimate was 1,574,281.

At the other end of the scale, Cameron County had an estimated 4,211 residents on July 1, 2025.

That means the most populous and least populous Pennsylvania counties are very different in size and population.

Population measure	County
Most populous	Philadelphia County
Least populous	Cameron County

Population figures can change each year, so I recommend checking the reference year before comparing Pennsylvania counties by population.

For example, a 2020 Census figure and a 2025 population estimate are different datasets. Mixing them in the same comparison can give readers the wrong impression.

Pennsylvania Counties by Area

Population does not tell us how large a county is geographically.

Lycoming County is the largest Pennsylvania county by land area. Its 2020 land area was about 1,228.92 square miles.

Montour County is the smallest Pennsylvania county by land area.

This creates an interesting contrast. Philadelphia County has a much larger population, while Lycoming County covers far more land.

I find it useful to keep these two measures separate:

Population tells you how many people live in a county.
Land area tells you how much geographic space the county covers.
Population density combines population and land area to show how closely people live together.

So, the largest county by area is not the largest county by population.

What Are the Classes of Pennsylvania Counties?

Pennsylvania counties are divided into classes based on population.

The current classification has nine categories, from First Class through Eighth Class, with a separate Second Class A category.

County class	Population range
First Class	1,500,000 or more
Second Class	1,000,000–1,499,999
Second Class A	500,000–999,999
Third Class	210,000–499,999
Fourth Class	145,000–209,999
Fifth Class	90,000–144,999
Sixth Class	45,000–89,999
Seventh Class	20,000–44,999
Eighth Class	Less than 20,000

The current distribution includes Philadelphia County as the only First Class county and Allegheny County as the only Second Class county. Bucks, Delaware, Lancaster, and Montgomery counties are in the Second Class A group.

The other counties fall into the Third through Eighth classes based on their population range.

How Many Counties Are in Each Class?

The current breakdown is:

First Class: 1 county
Second Class: 1 county
Second Class A: 4 counties
Third Class: 11 counties
Fourth Class: 9 counties
Fifth Class: 7 counties
Sixth Class: 24 counties
Seventh Class: 4 counties
Eighth Class: 6 counties

That adds up to all 67 Pennsylvania counties.

How Does County Government Work in Pennsylvania?

Pennsylvania counties are separate local government units that operate alongside cities, boroughs, and townships.

This means a person can be a resident of a county and also live in a city, borough, or township within that county. Counties and municipalities have different responsibilities.

County governments can provide services related to:

Courts and judicial administration
Corrections
Elections
Emergency management
Public health
Human services
Property assessment
Land-use planning
Environmental planning
Community and economic development

The exact structure can vary by county.

Many counties use county commissioners, while some have adopted home-rule government structures.

What Is a Home Rule County?

A home-rule county has adopted a charter that gives its local government more control over its structure and powers than the standard county system.

This is one reason Pennsylvania county government does not look exactly the same in every part of the state.

For a simple county list, you do not need to study these differences. But if you are researching how a particular Pennsylvania county operates, its form of government can matter.

Philadelphia County and the City of Philadelphia

Philadelphia County can cause confusion because the county and the City of Philadelphia cover the same geographic area.

Philadelphia County is also a county in Pennsylvania, while Philadelphia is the city that occupies that county.

This is different from many Pennsylvania counties where a city, borough, or township exists inside the county as a separate municipality.

Philadelphia is also Pennsylvania’s First Class county under the current population-based county classification.

So if you see Philadelphia County in a Pennsylvania counties list, it is not a mistake. It is one of the state’s 67 counties.

Pennsylvania County Codes

Pennsylvania assigns every county a state county number from 1 through 67.

For example:

County	Pennsylvania county number
Adams	1
Allegheny	2
Armstrong	3
Beaver	4
Bedford	5
Philadelphia	51
Pittsburgh	—
York	67

Pittsburgh is a city, not a county, so it does not have its own Pennsylvania county number. It is located in Allegheny County.

The complete state numbering system runs from Adams County at 1 through York County at 67, with each county assigned its own number.

Pennsylvania FIPS Codes

Federal geographic systems use a five-digit FIPS code for Pennsylvania counties.

Pennsylvania’s state FIPS code is 42, followed by a three-digit county code.

For example:

Adams County: 42001
Allegheny County: 42003
Armstrong County: 42005
Beaver County: 42007
Bedford County: 42009
Lycoming County: 42081
Philadelphia County: 42101
York County: 42133

These codes are useful in Census data, geographic databases, mapping systems, statistics, and other government datasets.

When Were Pennsylvania Counties Established?

Pennsylvania’s counties were created over a long period as the population grew and new areas needed separate local governments.

Some of the oldest counties date to the colonial period. Philadelphia, Bucks, and Chester were established in 1682. Other counties were created much later from parts of existing counties.

For example:

Lancaster County: 1729
York County: 1749
Berks County: 1752
Cumberland County: 1750
Allegheny County: 1788
Lycoming County: 1795
Lackawanna County: 1878

Lackawanna County is the newest of Pennsylvania’s current counties. It was created from Luzerne County in 1878.

Why Were New Counties Created?

As settlements expanded, traveling to a courthouse or county office could become difficult.

Creating a new county placed government services closer to residents. New counties were often formed from parts of existing counties as population and settlement patterns changed.

This process explains why some counties are much older than others.

Pennsylvania Counties and County Seats

A county seat is the administrative center of a county.

Some county seats have the same name as the county:

Beaver County — Beaver
Butler County — Butler
Erie County — Erie
Indiana County — Indiana
Mercer County — Mercer
Warren County — Warren
Washington County — Washington
York County — York

Others have different names:

Adams County — Gettysburg
Allegheny County — Pittsburgh
Bucks County — Doylestown
Chester County — West Chester
Dauphin County — Harrisburg
Lancaster County — Lancaster
Lycoming County — Williamsport
Montgomery County — Norristown
Philadelphia County — Philadelphia

I recommend using the county-seat table above as the quick reference rather than trying to memorize all 67 locations.

Pennsylvania Counties at a Glance

Here are some of the main facts in one place:

Fact	Answer
Number of counties	67
Largest by land area	Lycoming County
Smallest by land area	Montour County
Most populous	Philadelphia County
Least populous	Cameron County
First Class county	Philadelphia County
Second Class county	Allegheny County
Newest county	Lackawanna County
Pennsylvania county numbers	1–67
State FIPS code	42

The population figures above use the July 1, 2025 estimates where stated. County size comes from geographic data, so these measures should not be treated as interchangeable.

Final Take on Pennsylvania Counties

Pennsylvania has 67 counties, and each has its own county seat, geographic area, population, history, and local government structure.

For a quick reference, the most useful place to start is the complete county and county-seat list. If you need deeper information, population, area, county classification, historical dates, and county codes give you a clearer picture of how the counties differ.

I recommend keeping population and land area separate when comparing Pennsylvania counties. A county can cover a large part of the state while having a relatively small population, while a smaller county such as Philadelphia can have a much larger population.

Frequently Asked Questions About Pennsylvania Counties

How many counties are in Pennsylvania?

Pennsylvania has 67 counties.

What is the largest county in Pennsylvania by area?

Lycoming County is the largest Pennsylvania county by land area, with about 1,228.92 square miles of land according to the 2020 geographic measure.

What is the smallest county in Pennsylvania by area?

Montour County is the smallest Pennsylvania county by land area.

What is the most populous county in Pennsylvania?

Philadelphia County is the most populous county. Its July 1, 2025 population estimate was 1,574,281.

What is the least populous county in Pennsylvania?

Cameron County is the least populous county. Its July 1, 2025 population estimate was 4,211.

What is the county seat of Pennsylvania?

Pennsylvania does not have one county seat because it has 67 counties. Each county has its own county seat.

For example, Harrisburg is the county seat of Dauphin County, Pittsburgh is the county seat of Allegheny County, and Philadelphia is the county seat of Philadelphia County.

What is the newest county in Pennsylvania?

Lackawanna County is the newest current county in Pennsylvania. It was created in 1878 from part of Luzerne County.

What are the oldest counties in Pennsylvania?

Philadelphia, Bucks, and Chester counties date to 1682 and are among the oldest counties in Pennsylvania.

Is Philadelphia a county or a city?

Philadelphia is both a city and the county seat of Philadelphia County. The city and county cover the same geographic area, which makes Philadelphia different from most other Pennsylvania counties.

What is the county number for Philadelphia?

Philadelphia County is County Number 51 in Pennsylvania’s state county numbering system.

How many classes of counties are there in Pennsylvania?

Pennsylvania uses nine county classes: First Class, Second Class, Second Class A, Third Class, Fourth Class, Fifth Class, Sixth Class, Seventh Class, and Eighth Class. The classes are based on population ranges.