Johnson County Population 2018

Johnson County's estimated population is 149,210 with a growth rate of 1.76% in the past year according to the most recent United States census data. Johnson County is the 4th largest county in Iowa.

Year Population Growth Growth Rate
2017149,2102,5771.76%
2016146,6332,1061.46%
2015144,5272,4271.71%
2014142,1002,4471.75%
2013139,6532,8702.10%
2012136,7833,1092.33%
2011133,6742,3811.81%
2010131,29335,17436.59%
199096,11914,40217.62%
198081,7179,59013.30%
197072,12718,46434.41%
196053,6637,90717.28%
195045,75612,56537.86%
194033,1912,9159.63%
193030,2763,81414.41%
192026,4625482.11%
191025,9141,0974.42%
190024,8171,7357.52%
189023,082-2,347-9.23%
188025,4295312.13%
187024,8987,32541.68%
186017,57313,101292.96%
18504,4722,981199.93%
18401,4910.00%

Johnson County Population Growth

Population Data via

Johnson County Race Data

Race Population Percentage
White122,14481.86%
Black or African American9,3966.30%
Asian9,2236.18%
Two or More Races3,3212.23%
American Indian and Alaska Native4220.28%
Native Hawaiian and Other Pacific Islander610.04%

Johnson County Population Pyramid

0k2k4k6k8k10k12k Male Population0k2k4k6k8k10k12k Female Population8580757065605550454035302520151050
Data Sources
  1. US Census City/Town Population estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. Population of States and Counties of the United States: 1790 - 1990