According to the United States Census Bureau, the town of Glen Alpine has a total area of 2.2 square miles (5.6 km2), all land.

[6] As of the 2020 United States census, there were 1,529 people, 635 households, and 481 families residing in the town.

As of the census[4] of 2000, there were 1,090 people, 423 households, and 307 families residing in the town.

There were 443 housing units at an average density of 239.0 per square mile (92.3/km2).

24.1% of all households were made up of individuals, and 11.3% had someone living alone who was 65 years of age or older.