Lee’s Summit is located in two counties in Missouri, Jackson and Cass – making it the 6th largest city in Missouri. The most common industries in the city are healthcare, retail trade, and professional and scientific research. Lee’s Summit top employers are Lee’s Summit R-7 Schools, the University of Central Missouri, City of Lee’s Summit, and Truman Medical Center. Get your virtual mailbox now for a street address in the heart of Missouri and 24/7 postal mail management.