Leesburg is a city in Lake County, Florida, United States. The population was 15,956 at the 2000 census. As of 2005, the population recorded by the U.S. Census Bureau is 19,086.. Leesburg is located in central Florida, between Lake Harris and Lake Griffin, at the head of the Oklawaha River system. Leesburg is the home of Lake-Sumter Community College with campuses also in Clermont, Florida and Sumterville, Florida. Leesburg apartments for rent comparison page shows most up to date rent information on Leesburg apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.