Sinclair Township is a township in Jewell County, Kansas, United States. As of the 2000 census, its population was 67.
Sinclair Township covers an area of 35.34 square miles (91.52 square kilometers); of this, 0.99 square miles (2.57 square kilometers) or 2.81 percent is water.
(This list is based on USGS data and may include former settlements.)
The township contains three cemeteries: Fairview, Laurel Hill and Switzers Gap.