Kearny County Population 2018
Kearny County's estimated population is 3,960 with a growth rate of 1.54% in the past year according to the most recent United States census data. Kearny County is the 75th largest county in Kansas.
| Year | Population | Growth | Growth Rate |
| 2017 | 3,960 | 60 | 1.54% |
| 2016 | 3,900 | -34 | -0.86% |
| 2015 | 3,934 | -5 | -0.13% |
| 2014 | 3,939 | 19 | 0.48% |
| 2013 | 3,920 | -62 | -1.56% |
| 2012 | 3,982 | 17 | 0.43% |
| 2011 | 3,965 | -37 | -0.92% |
| 2010 | 4,002 | -25 | -0.62% |
| 1990 | 4,027 | 592 | 17.23% |
| 1980 | 3,435 | 388 | 12.73% |
| 1970 | 3,047 | -61 | -1.96% |
| 1960 | 3,108 | -384 | -11.00% |
| 1950 | 3,492 | 967 | 38.30% |
| 1940 | 2,525 | -671 | -20.99% |
| 1930 | 3,196 | 579 | 22.12% |
| 1920 | 2,617 | -589 | -18.37% |
| 1910 | 3,206 | 2,099 | 189.61% |
| 1900 | 1,107 | -464 | -29.54% |
| 1890 | 1,571 | 1,412 | 888.05% |
| 1880 | 159 | 0.00% |