[4] Codington County comprises the Watertown, SD Micropolitan Statistical Area.

Codington County terrain consists of rolling hills dotted with lakes and ponds, especially in the southwest portion.

[5] The terrain is higher on the county's east and west sides, and generally slopes to the south.

In terms of ancestry, 54.3% were German, 22.6% were Norwegian, 9.6% were Irish, 6.7% were English, and 3.3% were American.

In no national election since 1976 has the county selected the Democratic Party candidate.