County Line is located at 33°49'10.722" north, 86°43'45.433" west (33.819645, -86.729287),[2] 1.3 miles (2.1 km) east of Trafford.

According to the United States Census Bureau, the town has a total area of 0.9 square miles (2.3 km2), all land.

The racial makeup of the town was 95.72% White, 2.72% Black or African American, and 1.56% from two or more races.

About 13.8% of families and 17.4% of the population were below the poverty line, including 30.4% of those under the age of eighteen and 9.1% of those sixty five or over.

The town's government consists of a mayor and five city council members.