Ohio contains 88 counties, and understanding how they are organized by number is essential for anyone working with government records, geographic information systems, postal data, or historical research. Most people don't realize that "counties by number" can refer to a few different systems, including standard alphabetical numbering, federal FIPS codes, and historical license plate prefixes.
Alphabetical numbering remains the most common system for quick lookup tasks, mapping, and reference guides. In this framework, Adams County starts the list as number one, while Wyandot County finishes it as number eighty-five—wait, let's look closer at the full count. Ohio has 88 distinct counties, and sorting them alphabetically assigns each a permanent integer from 1 to 88. This guide breaks down the complete master list, explains how numerical administrative codes function across state agencies, and answers common questions about Ohio's regional layout.
The Complete List of Ohio Counties by Alphabetical Number
When sorted strictly from A to Z, each of Ohio's 88 counties receives a numerical identifier from 1 to 88. This sequence is widely used by researchers, local agencies, and mapping tools to maintain a consistent order that doesn't change with population shifts.
- Adams
- Allen
- Ashland
- Ashtabula
- Athens
- Auglaize
- Belmont
- Brown
- Butler
- Carroll
- Champaign
- Clark
- Clermont
- Clinton
- Columbiana
- Coshocton
- Crawford
- Cuyahoga
- Darke
- Defiance
- Delaware
- Erie
- Fairfield
- Fayette
- Franklin
- Fulton
- Gallia
- Geauga
- Greene
- Guernsey
- Hamilton
- Hancock
- Hardin
- Harrison
- Henry
- Highland
- Hocking
- Holmes
- Huron
- Jackson
- Jefferson
- Knox
- Lake
- Lawrence
- Licking
- Logan
- Lorain
- Lucas
- Madison
- Mahoning
- Marion
- Medina
- Meigs
- Mercer
- Miami
- Monroe
- Montgomery
- Morgan
- Morrow
- Muskingum
- Noble
- Ottawa
- Paulding
- Perry
- Pickaway
- Pike
- Portage
- Preble
- Putnam
- Richland
- Ross
- Sandusky
- Scioto
- Seneca
- Shelby
- Stark
- Summit
- Trumbull
- Tuscarawas
- Union
- Van Wert
- Vinton
- Warren
- Washington
- Wayne
- Williams
- Wood
- Wyandot
Understanding FIPS Numerical Codes for Ohio Counties
If you are dealing with government data, tax records, or public health statistics, the numbers you need aren't alphabetical rankings. Instead, agencies rely on Federal Information Processing Series (FIPS) codes. These are standardized three-digit codes assigned in odd-numbered increments to every county in the state.
For instance, Adams County holds FIPS code 001, Allen County is 003, and Ashland County is 005. Using FIPS codes prevents confusion when county names are misspelled or abbreviated in large databases. The U.S. Census Bureau relies heavily on these identifiers to track demographic shifts, housing data, and economic output across local jurisdictions.
Historical License Plate Codes and Administrative Systems
Long-time residents often look for numbers on older Ohio license plates or Department of Transportation documents. Historically, Ohio vehicle registrations used numerical prefixes or letter codes to denote the county of origin. While modern standard plates have moved away from strict numerical county prefixes on every design, specialized codes still appear in logistics and civil engineering maps managed by the Ohio Department of Transportation.
These transportation districts group counties by operational regions rather than strict alphabetical order. For example, ODOT district boundaries combine rural and urban counties to streamline road maintenance, winter snowplow deployment, and infrastructure funding.
Common Mistakes to Avoid When Working with County Data
People often run into trouble when mixing up different numbering conventions. Here are a few errors you'll want to avoid:
- Assuming alphabetical rank equals the FIPS code. Alphabetical lists run sequentially from 1 to 88, while FIPS codes skip numbers and use three digits (001, 003, 005, etc.).
- Forgetting that county names change position if you sort by population or geographic size instead of alphabetizing.
- Treating historical license plate prefixes as current mailing or GIS standards.
Frequently Asked Questions
Which Ohio county has the largest population?
Franklin County, which contains the state capital of Columbus, holds the largest population, closely followed by Cuyahoga County (Cleveland) and Hamilton County (Cincinnati).
How many total counties are in Ohio?
Ohio contains exactly 88 counties, a number that has remained unchanged since Vinton County was established in 1850 as the final addition.
What is the smallest county in Ohio by land area?
Lake County, located along the southern shore of Lake Erie, is the smallest county by square mileage, though it maintains a dense suburban population.
Where can I find official boundaries for mapping software?
GIS professionals and researchers typically download official county shapefiles directly from the Ohio Secretary of State or federal geospatial repositories to ensure accurate border alignments.
