Clermont is the most populous city in Lake County, within the U.S. state of Florida. The population was 43,021 in 2020. It is about 22 miles west …Clermont is the most populous city in Lake County, within the U.S. state of Florida. The population was 43,021 in 2020. It is about 22 miles west of Orlando and 22 miles southeast of Leesburg. The city is largely residential in character and its economy is centered in retail trade, lodging, and tourism-oriented restaurants and bars. It is part of the Orlando–Kissimmee–Sanford Metropolitan Statistical Area.