The largest county in New York
There are two right answers. By land area it is St. Lawrence County; by population it is Kings County. Which one you want depends on what you meant by largest.
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025. Retrieved 30 August 2026.
By land area
| Rank | Name | Land area | Population |
|---|---|---|---|
| 1 | St. Lawrence County | 2,680 sq mi | 105,488 |
| 2 | Essex County | 1,794 sq mi | 36,438 |
| 3 | Hamilton County | 1,717 sq mi | 5,006 |
| 4 | Franklin County | 1,629 sq mi | 46,500 |
| 5 | Delaware County | 1,443 sq mi | 44,305 |
| 6 | Herkimer County | 1,411 sq mi | 59,219 |
| 7 | Steuben County | 1,391 sq mi | 91,855 |
| 8 | Cattaraugus County | 1,308 sq mi | 75,390 |
| 9 | Lewis County | 1,276 sq mi | 26,479 |
| 10 | Jefferson County | 1,268 sq mi | 111,540 |
By population
| Rank | Name | Population | Density |
|---|---|---|---|
| 1 | Kings County | 2,653,963 | 38,254 per sq mi |
| 2 | Queens County | 2,358,182 | 21,690 per sq mi |
| 3 | New York County | 1,664,862 | 73,478 per sq mi |
| 4 | Suffolk County | 1,546,090 | 1,697 per sq mi |
| 5 | Bronx County | 1,406,332 | 33,325 per sq mi |
| 6 | Nassau County | 1,398,939 | 4,916 per sq mi |
| 7 | Westchester County | 1,015,743 | 2,358 per sq mi |
| 8 | Erie County | 946,741 | 908 per sq mi |
| 9 | Monroe County | 750,506 | 1,142 per sq mi |
| 10 | Richmond County | 501,290 | 8,715 per sq mi |
And the smallest
More on New York
Rebuilt from source data 30 August 2026. How these figures are produced.