The Town of Underhill is a rural township in the southwest corner of Oconto County in northeastern Wisconsin.

It is a 6 mile by 6 mile square area of woodlands, agricultural fields, lake lots, and widely dispersed isolated homes. It is in the Central Standard time zone. 

Most of Berry Lake is within the Township of Underhill. Berry Lake with many year around homes and summer places, plus a youth camp and a campgrounds.

The Oconto River flows generally north to south in the eastern portion of the township, with bridges at Hintz and the village of Underhill. Both Hintz and Underhill have parks and boat landings unto the Oconto River. Almost the entire township is privately owned lands.