St. Louis Mills, also known as St. Louis Outlet Mall, was a shopping mall in Hazelwood, Missouri, a suburb of St. Louis, Missouri, United States. Opened in 2003, the mall struggled with tenancy for many years before closing in 2019. The first redevelopment effort, a sports complex called the Powerplex STL, operated from 2019 to 2023. It was then redeveloped into the Hazelwood Business Park.