Duncan is a very small town located in the state of South Carolina. With a population of 4,276 people and two associated neighborhoods, Duncan is the 89th largest community in South Carolina. Duncan has seen a significant amount of newer housing growth in recent years. Quite often, new home construction is the result of new residents moving in who are middle class or wealthier, attracted by jobs, a healthy local economy, or other amenities as they leave nearby or far away areas for greener pastures. This seems to be the case in Duncan, where the median household income is $58,112.00.

As is often the case in a small town, Duncan doesn't have a public transportation system that people use for their commute.

The education level of Duncan citizens is substantially higher than the typical US community, as 31.56% of adults in Duncan have at least a bachelor's degree.

The per capita income in Duncan in 2022 was $26,367, which is middle income relative to South Carolina, and lower middle income relative to the rest of the US. This equates to an annual income of $105,468 for a family of four.

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

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