[5] Cedar Township was established in March 1887.

It is bordered to the west and northwest by Marquette Township, to the northeast by Chippewa County, and to the south by Lake Huron.

According to the U.S. Census Bureau, the township has a total area of 101.60 square miles (263.14 km2), of which 78.97 square miles (204.53 km2) are land and 22.63 square miles (58.61 km2) (22.27%) are water.

[7] The southern part of the township is home to numerous bays and inlets of Lake Huron, as well the Les Cheneaux Islands.

The entire township is served by Les Cheneaux Community Schools within the township in Cedarville.