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 (LSCC) with campuses also in Clermont, Florida and Sumterville, Florida. Leesburg is located at 28° 48' 38" N 081° 53' 0" W.

Leesburg was first settled in 1857 by Evander McIver Lee. Several of Evander Lee's brothers followed him to the area. One of these brothers, Calvin Lee, was credited with giving the town its name.

The city of Leesburg was first incorporated in 1875, and was the county seat of Sumter County for a time until Lake County was formed in 1887.

In the early 20th century, Leesburg was an important center for watermelon production. In 1930, Leesburg held its first Watermelon Festival, an annual tradition that would last until watermelon production in the area dwindled to the point that watermelons for the last festival had to be brought in from outside the area.

In 1938, the Works Progress Administration (WPA) began work on the Venetian Gardens waterside park, on the shores of Lake Harris. The canals and gardens of this park have been a centerpiece of the community ever since.

The citrus industry was the principal business in Leesburg for many years, until devastating freezes in December 1983 and January 1985 persuaded growers to move their groves further down the Florida peninsula.

Today, most of Leesburg's growth and economic development is the result of the increasing popularity of the area as a retirement destination and the rapid growth of nearby Orlando.