Montgomery County Population 2018
Montgomery County's estimated population is 826,075 with a growth rate of 0.66% in the past year according to the most recent United States census data. Montgomery County is the 3rd largest county in Pennsylvania.
| Year | Population | Growth | Growth Rate |
| 2017 | 826,075 | 5,419 | 0.66% |
| 2016 | 820,656 | 2,787 | 0.34% |
| 2015 | 817,869 | 1,922 | 0.24% |
| 2014 | 815,947 | 3,109 | 0.38% |
| 2013 | 812,838 | 3,926 | 0.49% |
| 2012 | 808,912 | 3,726 | 0.46% |
| 2011 | 805,186 | 4,205 | 0.52% |
| 2010 | 800,981 | 122,870 | 18.12% |
| 1990 | 678,111 | 34,490 | 5.36% |
| 1980 | 643,621 | 19,822 | 3.18% |
| 1970 | 623,799 | 107,117 | 20.73% |
| 1960 | 516,682 | 163,614 | 46.34% |
| 1950 | 353,068 | 63,821 | 22.06% |
| 1940 | 289,247 | 23,443 | 8.82% |
| 1930 | 265,804 | 66,494 | 33.36% |
| 1920 | 199,310 | 29,720 | 17.52% |
| 1910 | 169,590 | 30,595 | 22.01% |
| 1900 | 138,995 | 15,705 | 12.74% |
| 1890 | 123,290 | 26,796 | 27.77% |
| 1880 | 96,494 | 14,882 | 18.24% |
| 1870 | 81,612 | 11,112 | 15.76% |
| 1860 | 70,500 | 12,209 | 20.94% |
| 1850 | 58,291 | 11,050 | 23.39% |
| 1840 | 47,241 | 7,835 | 19.88% |
| 1830 | 39,406 | 3,613 | 10.09% |
| 1820 | 35,793 | 6,090 | 20.50% |
| 1810 | 29,703 | 5,553 | 22.99% |
| 1800 | 24,150 | 1,221 | 5.33% |
| 1790 | 22,929 | 0.00% |