Thief River Falls is a city located in Pennington County Minnesota. It is also the county seat of Pennington County. With a 2020 population of 8,884, it is the 107th largest city in Minnesota and the 3352nd largest city in the United States . Thief River Falls is currently growing at a rate of 0.32% annually and its population has increased by 3.63% since the most recent census, which recorded a population of 8,573 in 2010. Thief River Falls reached it's highest population of 9,105 in 1980. Spanning over 6 miles, Thief River Falls has a population density of 1,569 people per square mile.
The average household income in Thief River Falls is $62,262 with a poverty rate of 13.51%. The median rental costs in recent years comes to $693 per month, and the median house value is $135,700. The median age in Thief River Falls is 39.1 years, 36.5 years for males, and 41.9 years for females.