County facts · Land area · October 21, 2026

Largest Counties in Oklahoma by Area and Population

The largest Oklahoma counties by land area and by 2023 population, plus the smallest, county seats and a link to each official parcel map.

Looking for the largest counties in Oklahoma? Oklahoma has 77 counties covering about 68,597 square miles of land, based on the Census Bureau's 2020 Gazetteer. The largest by land area is Osage County, at about 2,247 square miles, roughly 6.0 times the size of the smallest, Marshall County (371 sq mi). Measured by people instead, the largest is Oklahoma County, with about 808,866 residents in the Census Bureau's July 1, 2023 estimate.

Each table below links the county's Platbookmapper page and its official parcel viewer, so you can go straight from the numbers to the property lines.

Oklahoma counties at a glance

• Counties: 77
• Land area: about 68,597 sq mi, plus about 1,303 sq mi of water inside county lines
• Residents, 2023 estimates: about 4,053,824, or about 59 people per square mile of land
• Median county land area: about 803 sq mi
• With a verified public parcel viewer in our directory: 77 of 77 (64 of them through a statewide viewer)

The 10 largest Oklahoma counties by land area

Together these 10 cover about 24% of Oklahoma's land area and hold about 6% of its residents.

The 10 most populous Oklahoma counties

These 10 hold about 62% of Oklahoma's residents in the 2023 estimates.

The 5 smallest Oklahoma counties by land area

Most and least crowded

• Most people per square mile: Tulsa County, about 1,198 (then Oklahoma County, 1,141, and Cleveland County, 559)
• Fewest people per square mile: Cimarron County, about 1.2 (then Beaver County, 2.8, and Roger Mills County, 2.9)

Counties with the most water

The Census Bureau reports water separately from land. It counts lakes, reservoirs, rivers and, for coastal and Great Lakes counties, the water inside the county boundary.

• McIntosh County: about 94 sq mi of water, 13% of its total area
• Pittsburg County: about 72 sq mi of water, 5% of its total area
• Osage County: about 57 sq mi of water, 2% of its total area

Using these numbers in a land search

• Land area is not parcel count. A large rural county can hold fewer parcels than a small suburban one, so size alone says little about how busy its parcel map is.
• Search, don't scroll. In a big county, type an address, owner name or parcel number into the viewer's search box, where it has one, instead of panning across the map.
• Records follow the county line. Deeds, plats and tax bills are kept by the county where the parcel sits, so a tract that crosses a county line usually has a parcel number in each county.
• Rounded figures. Land and water areas are rounded to whole square miles. People per square mile is the 2023 estimate divided by land area.

Related guides

• Oklahoma county GIS websites by viewer
• Oklahoma landowner maps for hunting
• Arkansas–Oklahoma border counties
• Kansas–Oklahoma border counties
• Oklahoma–Texas border counties

More: All Oklahoma counties on Platbookmapper

Sources

• U.S. Census Bureau Gazetteer files, 2020 county land and water area.
• U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2023 (July 1, 2023 estimates)
• Platbookmapper county GIS directory (live data file behind our county pages, pulled October 21, 2026) for each county's official parcel viewer.
• County seats: Wikidata (county seat property), cross-checked against Census place names.