According to the United States Census Bureau, the city has a total area of 4.39 square miles (11.37 km2), all of it land.

[8] At the 2020 census there were 4,893 people, 2,288 households, and 1,275 families living in the city.

There were 2,348 housing units at an average density of 534.9 per square mile (206.5/km2).

There were 2,410 housing units at an average density of 549.0 per square mile (212.0/km2).

At the 2000 census there were 5,282 people, 2,204 households, and 1,498 families living in the city.

There were 2,306 housing units at an average density of 528.2 per square mile (203.9/km2).

A major Harlan employer is CDS Global, the Des Moines-based fulfillment house owned by the Hearst media conglomerate.

Since this company provides subscription services for hundreds of periodicals, it is common to see a Harlan P.O.

[15] The school district also serves residents of Jacksonville, Corley, Defiance, Panama, Portsmouth, Earling, and Westphalia.

The district's racial demographics are 91.4% White, 5.7% Hispanic, 0.8% African American, and 2% non-white of other minorities.

A department of St Michael's Catholic Church, it is the only private school in Harlan.