Eureka Township lies near the western boundary line of Dakota County, and is located within its southern half.

The city of Hampton is nearby to the east, but does not border the township.

The city of Northfield in Rice County is nearby to the south-southeast, but does not border the township.

There were 501 housing units at an average density of 14.2 per square mile (5.5/km2).

14.3% of all households were made up of individuals, and 4.4% had someone living alone who was 65 years of age or older.