Franklin County, Illinois Population 2019
Franklin County, Illinois's estimated population is 39,004 with a growth rate of -0.23% in the past year according to the most recent United States census data. Franklin County, Illinois is the 34th largest county in Illinois.
| Year | Population | Growth | Growth Rate |
| 2018 | 38,701 | -303 | -0.78% |
| 2017 | 39,004 | -89 | -0.23% |
| 2016 | 39,093 | -297 | -0.75% |
| 2015 | 39,390 | -55 | -0.14% |
| 2014 | 39,445 | -108 | -0.27% |
| 2013 | 39,553 | -309 | -0.78% |
| 2012 | 39,862 | -165 | -0.41% |
| 2011 | 40,027 | -8 | -0.02% |
| 2010 | 40,035 | -284 | -0.70% |
| 1990 | 40,319 | -2,882 | -6.67% |
| 1980 | 43,201 | 4,872 | 12.71% |
| 1970 | 38,329 | -952 | -2.42% |
| 1960 | 39,281 | -9,404 | -19.32% |
| 1950 | 48,685 | -4,452 | -8.38% |
| 1940 | 53,137 | -6,305 | -10.61% |
| 1930 | 59,442 | 2,149 | 3.75% |
| 1920 | 57,293 | 31,350 | 120.84% |
| 1910 | 25,943 | 6,268 | 31.86% |
| 1900 | 19,675 | 2,537 | 14.80% |
| 1890 | 17,138 | 1,009 | 6.26% |
| 1880 | 16,129 | 3,477 | 27.48% |
| 1870 | 12,652 | 3,259 | 34.70% |
| 1860 | 9,393 | 3,712 | 65.34% |
| 1850 | 5,681 | 1,999 | 54.29% |
| 1840 | 3,682 | -401 | -9.82% |
| 1830 | 4,083 | 2,320 | 131.59% |
| 1820 | 1,763 | 0.00% |