Buckeye Township is a township in Ellis County, Kansas, United States. As of the 2020 census, its population was 391.
Buckeye Township covers an area of and contains no incorporated settlements. According to the USGS, it contains three cemeteries: Hyacinth, Saint Andrew and Saint Severin.
A post office was opened at Martin in 1875. The post office was discontinued in 1894. The Martin area was part of Saline Township until 1910, when it passed to Riverview Township, and ultimately was incorporated into Buckeye Township.