Seneca is a somewhat small city located in the state of South Carolina. With a population of 8,979 people and seven associated neighborhoods, Seneca is the 54th largest community in South Carolina.

The citizens of Seneca are slightly better educated than the national average of 21.84% for all cities and towns, with 24.97% of adults in Seneca having a bachelor's degree or advanced degree.

The per capita income in Seneca in 2022 was $30,963, which is upper middle income relative to South Carolina, and middle income relative to the rest of the US. This equates to an annual income of $123,852 for a family of four. However, Seneca contains both very wealthy and poor people as well.

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

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