Barnwell is a very small city located in the state of South Carolina. With a population of 4,588 people and four associated neighborhoods, Barnwell is the 81st largest community in South Carolina.

The percentage of adults in Barnwell who are college-educated is close to the national average for all communities of 21.84%: 18.70% of the adults in Barnwell have a bachelor's degree or advanced degree.

The per capita income in Barnwell in 2018 was $22,803, which is lower middle income relative to South Carolina, and low income relative to the rest of the US. This equates to an annual income of $91,212 for a family of four. However, Barnwell contains both very wealthy and poor people as well. Barnwell also has one of the higher rates of people living in poverty in the nation, with 35.94% of its population below the federal poverty line.

Barnwell is an extremely ethnically-diverse city. The people who call Barnwell home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Barnwell residents report their race to be Black or African-American, followed by White. Important ancestries of people in Barnwell include Jamaican, English, Scottish, German, and African.

The most common language spoken in Barnwell is English. Other important languages spoken here include Spanish and German/Yiddish.