Jeffersonville is a city and the county seat of Clark County, Indiana, United States, situated along the Ohio River. Locally, the city is often referred to by the abbreviated name Jeff. It lies directly across the Ohio River to the north of Louisville, Kentucky, along I-65. The population was 49,447 at the 2020 census. Jeffersonville began its existence as a settlement around Fort Finney after 1786 and was named after Thomas Jefferson in 1801, the year he took office.