Rushville is a city in Rushville Township, Rush County, Indiana, United States. The population was 6,185 at the 2020 census. The city is the …Rushville is a city in Rushville Township, Rush County, Indiana, United States. The population was 6,185 at the 2020 census. The city is the county seat of Rush County. It, like the county, was named in honor of Dr. Benjamin Rush, who signed the Declaration of Independence.