County facts · Land area · October 22, 2026

Largest Counties in Maine by Area and Population

The largest Maine 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 Maine? Maine has 16 counties covering about 30,845 square miles of land, based on the Census Bureau's 2020 Gazetteer. The largest by land area is Aroostook County, at about 6,671 square miles, roughly 26 times the size of the smallest, Sagadahoc County (254 sq mi). Measured by people instead, the largest is Cumberland County, with about 310,230 residents in the Census Bureau's July 1, 2023 estimate.

The tables below rank the counties both ways. Each row links to the county's Platbookmapper page and straight to its official parcel viewer.

Maine counties at a glance

• Counties: 16
• Land area: about 30,845 sq mi, plus about 4,535 sq mi of water inside county lines
• Residents, 2023 estimates: about 1,395,722, or about 45 people per square mile of land
• Median county land area: about 1,289 sq mi
• With a verified public parcel viewer in our directory: 16 of 16 (16 of them through a statewide viewer)

Every county in Maine points to the same statewide viewer in our directory, the Maine GeoLibrary Parcel Viewer, so one search box covers the whole state and the parcel pop-ups look the same on both sides of a county line.

The 10 largest Maine counties by land area

Together these 10 cover about 90% of Maine's land area and hold about 58% of its residents.

The 10 most populous Maine counties

These 10 hold about 86% of Maine's residents in the 2023 estimates.

The smallest Maine counties

With only 16 counties, the bottom of the list is short. The three smallest by land area are Sagadahoc County (about 254 sq mi, 37,513 residents), Knox County (about 365 sq mi, 40,977 residents) and Lincoln County (about 456 sq mi, 36,507 residents).

Most and least crowded

• Most people per square mile: Cumberland County, about 371 (then Androscoggin County, 243, and York County, 221)
• Fewest people per square mile: Piscataquis County, about 4.4 (then Aroostook County, 10, and Washington County, 12)

Counties with the most water

The Census Bureau reports water separately from land. It counts lakes, reservoirs, rivers and, along a coast or a Great Lake, the water inside the boundary.

• Knox County: about 779 sq mi of water, 68% of its total area
• Hancock County: about 758 sq mi of water, 32% of its total area
• Washington County: about 695 sq mi of water, 21% 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 on each side.
• Rounded figures. Land and water areas are rounded to whole square miles (one decimal for very small places). People per square mile is the 2023 estimate divided by land area.

Related guides

• Maine landowner maps for hunting
• Largest county in each state
• Largest counties in the US by land area

More: All Maine 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 22, 2026) for each official parcel viewer.
• County seats: Wikidata (county seat property), cross-checked against Census place names.