[3] The county is named for Captain John Simpson, a Kentucky militia officer who fought in Battle of Fallen Timbers in the Northwest Indian War, and was killed during the War of 1812 in the Battle of River Raisin.

[5] The county is located in the Pennyroyal Plateau region of the state.

24.20% of all households were made up of individuals, and 10.40% had someone living alone who was 65 years of age or older.

In contrast to the Western Coalfield and the eastern part of the Pennyroyal Plateau, Simpson County was not highly pro-Union during the Civil War.

As with all of rural Kentucky, the social liberalism of the Democratic Party – rejected by many southern whites[13] – has led to an increase in registered Republicans, and many people registered as Democrats vote for Republican candidates, especially at the national level.