[2] Formed in 1820, the county was named for Stephen Trigg, an officer in the American Revolutionary War who was killed at the Battle of Blue Licks, now in Robertson County, Kentucky.

That year the county's voters narrowly approved a referendum to repeal the prohibition on alcohol sales for off-premises consumption.

[5] Trigg County is part of the Clarksville, TN–KY Metropolitan Statistical Area.

Trigg had settled near Harrodsburg, Kentucky; during the American Revolutionary War, he served as an officer for the rebels and was killed on August 19, 1782, in the Battle of Blue Licks.

25.00% of all households were made up of individuals, and 11.60% had someone living alone who was 65 years of age or older.