[3] It is named for William Darke, an officer in the American Revolutionary War.

[5] As of the census[10] of 2000, there were 53,309 people, 20,419 households, and 14,905 families living in the county.

43.1% were of German, 20.1% American, 8.1% English, 6.8% Irish and 5.8% French ancestry according to Census 2000.

23.50% of all households were made up of individuals, and 11.00% had someone living alone who was 65 years of age or older.

As of the 2010 United States Census, there were 52,959 people, 20,929 households, and 14,673 families living in the county.

[14] Originally settled by numerous migrants from the South, Darke County supported Democratic presidential candidates prior to 1912.

Lyndon B. Johnson was the only Democratic candidate supported by county voters since then.

[16] School districts (this includes any school district with portions of the county, no matter how slight, even if the schools and/or administrative offices are in another county)[17] [18] Darke County has 25 places listed on the National Register of Historic Places, including the Darke County Courthouse, Sheriff's House, and Jail, and the Versailles Town Hall and Wayne Township House.

Darke County is home to the Eldora Speedway located near New Weston, which hosts many big events throughout the year.