Lake Henry Township is located in Township 123 North of the Arkansas Base Line and Range 33 West of the 5th Principal Meridian.

As of the census[1] of 2000, there were 330 people, 101 households, and 83 families residing in the township.

There were 103 housing units at an average density of 2.9 per square mile (1.1/km2).

There were 101 households, out of which 38.6% had children under the age of 18 living with them, 76.2% were married couples living together, 1.0% had a female householder with no husband present, and 17.8% were non-families.

14.9% of all households were made up of individuals, and 5.9% had someone living alone who was 65 years of age or older.