West Mifflin is a city located in Allegheny County Pennsylvania. With a 2020 population of 19,735, it is the 27th largest city in Pennsylvania and the 1883rd largest city in the United States . West Mifflin is currently growing at a rate of 0.09% annually but its population has decreased by -2.85% since the most recent census, which recorded a population of 20,313 in 2010. West Mifflin reached it's highest population of in . Spanning over 15 miles, West Mifflin has a population density of 1,389 people per square mile.
The average household income in West Mifflin is $67,049 with a poverty rate of 13.85%. The median rental costs in recent years comes to $640 per month, and the median house value is $99,000. The median age in West Mifflin is 46.1 years, 43.1 years for males, and 48.4 years for females.