As of the census[2] of 2000, there were 1,224 people, 457 households, and 350 families residing in the township.

There were 631 housing units at an average density of 21.1 per square mile (8.1/km2).

The racial makeup of the township was 99.59% White, 0.16% Native American, and 0.25% from two or more races.

19.7% of all households were made up of individuals, and 6.3% had someone living alone who was 65 years of age or older.

Amboy Township is served by two separate public school districts.