Plymouth is a city located in Hancock County Illinois. With a 2020 population of 460, it is the 905th largest city in Illinois and the 13675th largest city in the United States . Plymouth is currently declining at a rate of -0.65% annually and its population has decreased by -8.91% since the most recent census, which recorded a population of 505 in 2010. Plymouth reached it's highest population of in . Spanning over 1 miles, Plymouth has a population density of 815 people per square mile.
The average household income in Plymouth is $48,938 with a poverty rate of 23.69%. The median rental costs in recent years comes to $636 per month, and the median house value is $38,800. The median age in Plymouth is 46.2 years, 42.1 years for males, and 49.8 years for females.