Vermillion County lies in the western part of the U.S. state of Indiana between the Illinois border and the Wabash River. It was officially established in 1824 and was the fiftieth Indiana county to be formed. It is included in the Terre Haute, Indiana, Metropolitan Statistical Area. The county seat is Newport.
According to the 2010 census, the population was 16,212; It has a population density of about . The county contains seven incorporated towns with a total population of about 9,900, as well as several unincorporated communities; it is also divided into five townships which provide local services. An interstate highway, two U.S. routes, and five state roads cross the county, as does a major railroad line.
The first settlers in the area arrived in 1816, the same year that the state of Indiana was established. Vigo County was formed in 1818 and included the area that later became Parke and Vermillion counties. In 1821, Parke County was formed, and on January 2, 1824, the Indiana General Assembly created Vermillion County out of Parke County; the act took effect on February 1. The county seat was established at Newport later that year, and it has always remained there.
The county was named for the southbound Vermilion River, which flows nearby. The name is spelled in the French/Commonwealth English style with a double letter "l", in contrast to the American English spelling of the adjacent Vermilion County, Illinois. This is one of only a few cases in the United States in which a county borders a county with the same name in another state.
The Newport Hill Climb was first held in 1909. The event was started and stopped several times over the years, but the Newport Lions Club now runs the Newport Antique Auto Hill Climb; it has been held continuously since the 1960s and involves several hundred cars each year.