Leesburg has no commercial airport. The nearest major airport is Orlando International Airport, about 90 minutes southeast by car. Orlando Sanford International Airport is closer — roughly 45 minutes. Both offer car rental options, which is essentially the only practical way to reach Leesburg: there is no intercity bus service worth mentioning and no rail connection.
From Orlando, take the Florida Turnpike northwest to US-27 or US-441 north into Lake County. The drive is straightforward.
Most visitors arrive by car, and having one is necessary for getting around once you are there.