Cosmopolis is a city located in Washington. With a 2020 population of 1,716, it is the 175th largest city in Washington and the 8211th largest city in the United States. Cosmopolis is currently growing at a rate of 1.60% annually and its population has increased by 4.06% since the most recent census, which recorded a population of 1,649 in 2010. Cosmopolis reached it's highest population of 1,716 in 2021. Spanning over 2 miles, Cosmopolis has a population density of 1,233 people per square mile.
The average household income in Cosmopolis is $65,676 with a poverty rate of 6.06%. The median rental costs in recent years comes to $864 per month, and the median house value is $165,300. The median age in Cosmopolis is 43.9 years, 43.3 years for males, and 46 years for females. For every 100 females there are 107.5 males.