Sullivan is a very small city located in the state of Indiana. With a population of 4,232 people and two associated neighborhoods, Sullivan is the 144th largest community in Indiana. Sullivan has a large stock of pre-World War II architecture, making it one of the older and more historic cities in the country.

Being a small city, Sullivan does not have a public transit system used by locals to get to and from work.

The percentage of people in Sullivan with college degrees is quite a bit lower than the national average for cities and towns of 21.84%: just 11.94% of people over 25 have a bachelor's degree or advanced degree.

The per capita income in Sullivan in 2022 was $22,556, which is low income relative to Indiana and the nation. This equates to an annual income of $90,224 for a family of four. However, Sullivan contains both very wealthy and poor people as well.

The people who call Sullivan home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Sullivan residents report their race to be White, followed by Black or African-American. Important ancestries of people in Sullivan include German, Irish, English, Italian, and Dutch.

The most common language spoken in Sullivan is English. Other important languages spoken here include Italian and Polish.